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Genetics

Genetics Reveal Poor Oral Health in Mesolithic Era – Mirage News

Members of a hunter-gatherer group that lived in south-western Scandinavia during the Mesolithic era approximately 10,000 years ago may have been affected by tooth decay and gum disease, according to a study published in Scientific Reports.

Emrah Krdk, Anders Gtherstrm and colleagues sequenced the DNA found on three pieces of birch tar a substance made from heated birch bark that were excavated in the 1990s from Huseby Klev, Sweden and have been dated to between 9,890 and 9,540 years old. They created profiles of the microbial, plant, and animal species DNA found on each sample and compared these to those previously reported for modern human samples, ancient human dental plaque, and a 6,000 year old chewed birch tar sample

The authors found that the microbial profiles of the birch tar samples were most similar to microbes found in the modern human mouth, in ancient human dental plaque, and in a 6,000 year old chewed birch tar sample. This suggests that the samples from Huseby Klev were chewed by humans. They also found that they contained an increased abundance of several bacteria that are commonly associated with gum disease such as Treponema denticola, Streptococcus anginosus, and Slackia exigua and tooth decay such as Streptococcus sobrinus and Parascardovia denticolens. Based on the relative abundance of microbial species in the birch tar samples and using machine learning models, the authors estimate that the probability that members of the hunter-gatherer group were affected by gum disease is between 70 and 80%. The authors suggest that the wider use of teeth to perform tasks involving gripping, cutting and tearing in ancient hunter-gatherer societies may have increased their risk of coming into contact with microbial species that cause gum disease.

In addition to microbial DNA, the authors identified DNA sequences consistent with those from a range of plant and animal species, including hazelnut, apple, mistletoe, red fox, grey wolf, mallard, limpet, and brown trout. These could reflect the materials that members of the hunter-gatherer group chewed prior to the birch tar samples. The authors speculate that these materials could have included food sources, furs, and bone tools.

The findings highlight the poor oral health of a group of Mesolithic Scandinavian hunter-gatherers and provide insight into their diet, material use, and local environment.

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Genetics Reveal Poor Oral Health in Mesolithic Era - Mirage News

Genetics

Nova Siri Genetics strengthens its presence in Huelva, growing by 34% – FreshPlaza.com

The province of Huelva has become a strategic territory for Nova Siri Genetics, a company that specializes in the research and experimentation of new strawberry and berry varieties. "Huelva is the area in Europe where its activity has grown the most. In fact, in the current 2023-2024 campaign the producing companies have planted 50 million plants of the company's strawberry varieties."

"Even though the area planted with strawberries in the province of Huelva decreased by 5% this campaign, Nova Siri Genetics managed to considerably increase its activity, as these 50 million plants represent a 34% growth compared to the previous 2022-2023 campaign."

"NSG 2023Marimbella, NSG 207Gioelita, and NSG 465Rossetta are -in this order- Nova Siri Genetics most implanted varieties in the province of Huelva. All three are early strawberry varieties that allow producers to advance their supply of this fruit to November and December. These varieties yield quality fruits and outstanding volumes in terms of kilograms per hectare."

"In fact, in the province of Huelva, the Marimbella variety yields more than 50,000 kilograms of strawberries per hectare. It's Nova Siri Genetics program's most cultivated variety in this area of southwestern Spain, with a total of 31 million plants grown for the current campaign."

Joaqun Domnguez, Nova Siri Genetics' commercial manager for Spain and Morocco, highlighted "the rusticity of these varieties, as they are resistant to Botrytis and other diseases caused by the main fungal pathogens in the soil. In addition, these varieties yield strawberries with excellent organoleptic characteristics, such as aroma, flavor, shape, size, consistent pulp, and an elastic epidermis that allows them to have a long shelf life. Finally, their precocity guarantees producers will have fruits at the end of autumn and the beginning of winter."

According to Joaqun Domnguez, Nova Siri Genetics' mission is to provide varieties that meet the needs of producers and consumers. That's why the company is developing in the province of Huelva a program for the participatory selection of varieties, which is a continuation of participatory plant breeding and a key step in establishing the objectives of this action, involving the different participants in the chain (scientists, production companies, consultants, sales representatives, and consumers)."

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Nova Siri Genetics strengthens its presence in Huelva, growing by 34% - FreshPlaza.com

Physiology

Master of Science in Medical Physiology program admissions open office hour – The Daily | Case Western Reserve University

Case Western Reserve University students are invited to join the Master of Science in Medical Physiology program for a virtual admissions open office hour Thursday, Jan. 18, at 1 p.m.

Samantha Baker, director of admissions, will be available to answer questions about admissions, curriculum, enrichment experiences, life in Cleveland, student successes and more. This is a drop-in style session; there will not be a formal presentation.

Get more information.

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Master of Science in Medical Physiology program admissions open office hour - The Daily | Case Western Reserve University

Physiology

The Impact of GATAD2B Mutations on Brain Function and Development – Medriva

The Impact of GATAD2B Mutations on Brain Function and Development

One of the fundamental aspects of understanding neurodevelopmental disorders and intellectual disabilities is to explore the underlying genetic factors. A gene that has been drawing attention in recent years is GATAD2B. This gene is implicated in brain development and physiology, and mutations in it can lead to profound effects, particularly on cognitive function.

A recent study, focusing on the role of GATAD2B, utilized a mouse model with an inactivating mutation in Gatad2b. The research findings indicated that mutant Gatad2b mice exhibited behavioral and learning abnormalities similar to the human phenotype. These abnormalities were accompanied by abnormal cortical development and gene expression patterns, suggesting that GATAD2B mutations result in abnormal epigenetic transcriptional regulation of corticogenesis, thereby leading to intellectual disability.

Several scientific techniques were employed to understand the role and impact of GATAD2B mutations on brain development. Quantitative PCR was used to assess Gatad2b expression levels in the brain of mice, and Western blot analysis was performed to detect the Gatad2b protein. These techniques were coupled with histological analysis and behavioral tests to evaluate cognitive function in the mutant mice.

Furthermore, the research employed single-cell RNA sequencing to identify shared cell states across different samples. It also conducted gene ontology enrichment analysis to gain insights into the pathogenesis mechanisms associated with GATAD2B haploinsufficiency. The study included a detailed description of the experimental procedures and ethical considerations, ensuring the integrity of the scientific process.

The findings of this study contribute significantly to the understanding of GATAD2B and its implications for brain function and development. The observation of abnormal cortical development and gene expression in mutant mice provides valuable insights into the potential pathophysiological mechanisms underpinning neurodevelopmental disorders associated with GATAD2B mutations.

This research also highlights the potential of GATAD2B as a therapeutic target for neurological disorders. Given its role in regulating gene expression and its impact on cognitive function, targeting GATAD2B could pave the way for innovative therapies in neurodevelopmental disorders and intellectual disabilities.

For more information on the role of GATAD2B in brain development and physiology, you may refer to these resources:

They provide detailed information on the role of GATAD2B in brain development, its function in regulating gene expression, and its impact on neurodevelopmental disorders.

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The Impact of GATAD2B Mutations on Brain Function and Development - Medriva

Biology

Synthetic biology aims to tackle disease and give cells superpowers – Science News Explores

activate: (in biology) To turn on, as with a gene or chemical reaction.

amino acids: Simple molecules that occur naturally in plant and animal tissues and that are the basic building blocks of proteins.

antenna: (plural: antennae or antennas) In biology: Either of a pair of long, thin sensory appendages on the heads of insects, crustaceans and some other arthropods. (in physics) Devices for picking up (receiving) electromagnetic energy.

artery: Part of the bodys circulation system. There are several. Each is amajor tuberunning between the heart and blood vessels that will move blood to all parts of the body.

behavior: The way something, often a person or other organism, acts towards others, or conducts itself.

biology: The study of living things. The scientists who study them are known as biologists.

blood vessel: A tubular structure that carries blood through the tissues and organs.

cancer: Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.

carbon: A chemical element that is the physical basis of all life on Earth. It can self-bond, chemically, to form an enormous number of chemically, biologically and commercially important molecules.

carbon nanotube: A nanoscale, tube-shaped material, made from carbon that conducts heat and electricity well.

cardiologist: A doctor that specializes in the branch of medicine dealing with functions and diseases of the heart.

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells.

cell membrane: A structure that separates the inside of a cell from what is outside of it. Some particles are permitted to pass through the membrane.

chain reaction: An event that once started continues to keep itself going. Its a term frequently used to describe atomic fission in a nuclear power plant. By packing enough fuel closely enough together, neutrons released by fissioning atoms bombard neighboring atoms, inducing them to fission. This sets up a self-sustaining process.

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H2O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

chemical signal: A message made up of molecules that get sent from one place to another. Bacteria and some animals use these signals to communicate.

chemistry: The field of science that deals with the composition, structure and properties of substances and how they interact.

cholesterol: A fatty material in animals that forms a part of cell walls. In vertebrate animals, it travels through the blood in little vessels known as lipoproteins. Excessive levels in the blood can signal risks to blood vessels and heart.

clot: (in medicine) A collection of blood cells (platelets) and chemicals that collect in a small region, stopping the flow of blood.

conductive: Able to carry an electric current.

contract: To activate muscle by allowing filaments in the muscle cells to connect. The muscle becomes more rigid as a result.

current: (in electricity) The flow of electricity or the amount of charge moving through some material over a particular period of time.

defense: (in biology) A natural protective action taken or chemical response that occurs when a species confronts predators or agents that might harm it. (adj. defensive)

DNA: (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. It is built on a backbone of phosphorus, oxygen, and carbon atoms. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

electricity: A flow of charge, usually from the movement of negatively charged particles, called electrons.

electrode: A device that conducts electricity and is used to make contact with non-metal part of an electrical circuit, or that contacts something through which an electrical signal moves. (in electronics)Part of a semiconductor device (such as a transistor) that either releases or collects electronsor holes, or that can controltheir movement.

engineer: A person who uses science and math to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need.

generation: A group of individuals (in any species) born at about the same time or that are regarded as a single group. Your parents belong to one generation of your family, for example, and your grandparents to another. Similarly, you and everyone within a few years of your age across the planet are referred to as belonging to a particular generation of humans.

germ: Any one-celled microorganism, such as a bacterium orfungal species, or a virus particle. Some germs cause disease. Others can promote the health of more complex organisms, including birds and mammals. The health effects of most germs, however, remain unknown.

immune: (adj.) Having to do with immunity. (v.) Able to ward off a particular infection.

immune system: The collection of cells and their responses that help the body fight off infections and deal with foreign substances that may provoke allergies.

implant: A device manufactured to replace a missing biological structure, to support a damaged biological structure, or to enhance an existing biological structure. Examples include artificial hips, knees and teeth; pacemakers; and the insulin pumps used to treat diabetes.Or some device installed surgically into an animals body to collect information on the individual (such as its temperature, blood pressure or activity cycle).

infectious: An adjective that describes a type of microbe or virus that can be transmitted to people, animals or other living things.

limb: (in physiology) An arm or leg. (in botany) A large structural part of a tree that branches out from the trunk.

link: A connection between two people or things.

magnetic field: An area of influence created by certain materials, called magnets, or by the movement of electric charges.

membrane: A barrier which blocks the passage (or flow through) of some materials depending on their size or other features. Membranes are an integral part of filtration systems. Many serve that same function as the outer covering of cells or organs of a body.

molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O2), but water is made of two hydrogen atoms and one oxygen atom (H2O).

muscle: A type of tissue used to produce movement by contracting its cells, known as muscle fibers. Muscle is rich in protein, which is why predatory species seek prey containing lots of this tissue.

nanoparticle: A small particle with dimensions measured in billionths of a meter.

nerve: A long, delicate fiberthat transmits signalsacross the body of an animal. An animals backbone contains many nerves, some of which control the movement of its legs or fins, and some of which convey sensations such as hot, cold or pain.

network: A group of interconnected people or things. (v.) The act of connecting with other people who work in a given area or do similar thing (such as artists, business leaders or medical-support groups), often by going to gatherings where such people would be expected, and then chatting them up. (n. networking)

novel: Something that is clever or unusual and new, as in never seen before.

organ: (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that makes sense of nerve signals and a plants roots are organs that take in nutrients and moisture.

organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.

particle: A minute amount of something.

pH: A measure of a solutions acidity or alkalinity. A pH of 7 is perfectly neutral. Acids have a pH lower than 7; the farther from 7, the stronger the acid. Alkaline solutions, called bases, have a pH higher than 7; again, the farther above 7, the stronger the base.

plaque: An accumulation of materials in the body from the fluids that move through an area or bathe it. They can be minerals, proteins or other substances that collect as deposits. (in heart disease) Fatty deposits that accumulate in vessels as a result of a disease known as atherosclerosis. This plaque is made up of fat, cholesteroland other substances carried by the blood. Eventually these deposits will harden and narrow the internal openings of the arteries. This reduces the flow of oxygen and blood to organs throughout body.

podcast: A digital audio or video series that can be downloaded from the Internet to your computer or smartphone. Some podcasts also are shows that are broadcast on radio, television or other media.

pore: A tiny hole in a surface. On the skin, substances such as oil, water and sweat pass through these openings.

prosthetic: Adjective that refers to a prosthesis.

protein: A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Antibodies, hemoglobin and enzymes are all examples of proteins. Medicines frequently work by latching onto proteins.

retinitis pigmentosa: Also known as RP, this incurable family of genetic eye diseases causes cells in the retina light-sensitive tissue at the back of the eyeball to fail. Problems emerge in childhood. Most patients eventually go blind.

rhodopsin: A pigment molecule bound to the light-sensing protein opsin. Rhodopsins are found in red cells of the eye. They are extremely sensitive to light, but cannot sense color.

risk: The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard or peril itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

science fiction: A field of literary or filmed stories that take place against a backdrop of fantasy, usually based on speculations about how science and engineering will direct developments in the distant future. The plots in many of these stories focus on space travel, exaggerated changes attributed to evolution or life in (or on) alien worlds.

strategy: A thoughtful and clever plan for achieving some difficult or challenging goal.

synthetic: An adjective that describes something that did not arise naturally, but was instead created by people. Many synthetic materialshave been developed to stand in for natural materials, such as synthetic rubber, synthetic diamond or a synthetic hormone. Some may even have a chemical makeup and structure identical to the original.

synthetic biology: A research field in which scientists work on developing custom life forms in the lab. Because they make synthetic organisms, scientists who work in this field are known as synthetic biologists.

system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body's circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation's railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.

technology: The application of scientific knowledge for practical purposes, especially in industry or the devices, processes and systems that result from those efforts.

tissue: Made of cells, it is any of the distinct types of materials that make up animals, plants or fungi. Cells within a tissue work as a unit to perform a particular function in living organisms. Different organs of the human body, for instance, often are made from many different types of tissues.

wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion.

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Synthetic biology aims to tackle disease and give cells superpowers - Science News Explores

Biology

Ecological determinants of Cope’s rule and its inverse | Communications Biology – Nature.com

We determine phylogenies using a process-based community-evolution model that describes changes in two adaptive traits, body size and ecological niche. Body size is a key functional trait with well-documented ecological implication (e.g.,ref.48), and adaptation of this trait alone enables the emergence of trophically structured communities44,46 (see also the reviewin ref.63). The similarity in ecological niche plays a fundamental complementary role in scaling species interactions, with interaction strengths naturally being maximized among individuals occupying the same niche. Accounting for this second trait in our model is a critical prerequisite for more complex processes of evolutionary diversification and, therefore, for the emergence of richer and more realistic community structures64. Below, we explain how these two traits jointly determine demographic dynamics and how gradual adaptive change over evolutionary time creates complex trophically structured ecological communities, complete with their specific phylogenetic histories.

We consider communities comprising (N) heterotrophic species designated by the indices (i=1,ldots ,N) that are interacting among each other and with one basal autotrophic resource designated by the index (i=0). The communitys species richness (N) is changing dynamically, through processes of extinction and speciation, as detailed below. Each species (i) is characterized by its population density ({x}_{i}) and two adaptive traits describing the average body size ({s}_{i}) and ecological niche ({n}_{i}) of its individuals. FollowingBrnnstrmet al.44, we express ({s}_{i}) in nondimensional logarithmic form as ({r}_{i}={{{{mathrm{ln}}}}}({s}_{i}/{s}_{0})), where ({s}_{0}) is the size of the basal autotrophic resource. While population densities and body sizes are necessarily non-negative, niche traits can take non-negative and negative values. We fix the otherwise arbitrary origin of the niche traits by assuming ({n}_{0}=0) for the basal autotrophic resource without loss of generality(.) All model parameters are shown in Table1 together with their default values.

The demographic dynamics of the (N) heterotrophic species (i=1,ldots ,N) and of the one basal autotrophic resource (i=0) are described by LotkaVolterra equations,

$$overbrace{frac{,{dot{x}}_{i}}{{x}_{i}}}^{{{{{{rm{Growth}}}}}}}= -overbrace{,d({r}_{i}),}^{{{{{{rm{Intrinsic}}}}}},{{{{{rm{mortality}}}}}}}+overbrace{mathop{sum }limits_{j=0}^{N}beta P({n}_{i},{n}_{j})p({r}_{i},{r}_{j})lambda exp ({r}_{j}-{r}_{i}){x}_{j}}^{{{{{{rm{Gains}}}}}},{{{{{rm{from}}}}}},{{{{{rm{predation}}}}}}}\ -overbrace{mathop{sum }limits_{j=1}^{N}beta P({n}_{j},{n}_{i})p({r}_{j},{r}_{i}){x}_{j}}^{{{{{{rm{Losses}}}}}},{{{{{rm{from}}}}}},{{{{{rm{predation}}}}}}}-overbrace{mathop{sum }limits_{j=1}^{N}alpha C({n}_{i},{n}_{j})c({r}_{i},{r}_{j}){x}_{j}}^{{{{{{rm{Losses}}}}}},{{{{{rm{from}}}}}},{{{{{rm{competition}}}}}}}$$

(1a)

and

$$overbrace{frac{,{dot{x}}_{0}}{{x}_{0}}}^{{{{{{rm{Growth}}}}}}}=+overbrace{,{g}_{0},}^{{{{{{rm{Intrinsic}}}}}},{{{{{rm{growth}}}}}}}-overbrace{mathop{sum }limits_{j=1}^{N}beta p({r}_{j},0)P({n}_{j},0){x}_{j}}^{{{{{{rm{Losses}}}}}},{{{{{rm{from}}}}}},{{{{{rm{predation}}}}}}}-overbrace{{x}_{0}/{K}_{0}}^{{{{{{rm{Losses}}}}}},{{{{{rm{from}}}}}},{{{{{rm{competition}}}}}}},$$

(1b)

where ({dot{x}}_{i}) denotes the rate at which the population density ({x}_{i}) changes. The terms on the right-hand side of Eq. (1a) are the per-capita rates of, for the heterotrophic species, intrinsic mortality, gains from predation, losses from predation, and losses from interference competition, respectively. Similarly, the terms on the right-hand side of Eq. (1b) are the per-capita rates of, for the basal autotrophic resource, intrinsic growth, losses from predation, and losses from competition, respectively. Gains can be realized through increased fecundity, reduced mortality, or a mixture of both, and, likewise, losses can be realized through reduced fecundity, increased mortality, or a mixture of both.

We consider a species to be extant as long as its population density exceeds the threshold (epsilon); conversely, if and when a species population density falls below this threshold, it is considered extinct and is removed from the community. The parameter (epsilon) can thus be interpreted as a measure of extinction risk resulting from sensitivity to demographic and environmental stochasticity.

The rate of intrinsic mortality and the intensities of predation and interference competition depend on the two adaptive traits. To reflect the energetic advantages of a larger body size over a smaller one, the intrinsic mortality rate is assumed to decline allometrically with the body size ({s}_{i}), and thus exponentially with the logarithmic body size ({r}_{i}), according to an exponent (q), whose value is suggested by Peters48 to equal ~0.25,

$$dleft({r}_{i}right)={d}_{0}{left({s}_{i}/{s}_{0}right)}^{-q}={d}_{0}exp (-q{r}_{i}).$$

(2a)

The intensities of predation and interference competition between individuals of two species (i) and (j) occupying the same niche, ({n}_{i}={n}_{j},) are determined by the ratio of their body sizes ({s}_{i}), and thus by the difference of their logarithmic body sizes ({r}_{i}). A predator of species (i) and logarithmic body size ({r}_{i}) forages on a prey of species (j) and logarithmic body size ({r}_{j}) at an intensity that is assumed to be maximized when their logarithmic body sizes differ by a value (mu) that is optimal for predation,

$$p({r}_{i},{r}_{j})=exp left(-tfrac{1}{2}{({r}_{i}-{r}_{j}-mu )}^{2}/{sigma }_{{{{{{rm{p}}}}}}}^{2}-tfrac{1}{4}{({r}_{i}-{r}_{j})}^{4}/{gamma }_{{{{{{rm{p}}}}}}}^{4}right).$$

(2b)

Similarly the intensity of interference competition between individuals of two species (i) and (j) occupying the same niche and having logarithmic body sizes ({r}_{i}) and ({r}_{j}) is assumed to be symmetrical and maximal for individuals of equal body size,

$$c({r}_{i},{r}_{j})=exp left(-tfrac{1}{2}{({r}_{i}-{r}_{j})}^{2}/{sigma }_{{{{{{rm{c}}}}}}}^{2}-tfrac{1}{4}{({r}_{i}-{r}_{j})}^{4}/{gamma }_{{{{{{rm{c}}}}}}}^{4}right).$$

(2c)

The intensities of predation and interference competition, respectively, between individuals of two species (i) and (j) occupying different niches, ({n}_{i}, ne , {n}_{j}), are reduced by factors described by functions that decline with increasing niche separation,

$$P({n}_{i},{n}_{j})=exp left(-tfrac{1}{2}{({n}_{i}-{n}_{j})}^{2}/{sigma }_{{{{{rm{P}}}}}}^{2}-tfrac{1}{4}{({n}_{i}-{n}_{j})}^{4}/{gamma }_{{{{{rm{P}}}}}}^{4}right)$$

(2d)

and

$$C({n}_{i},{n}_{j})=exp left(-tfrac{1}{2}{({n}_{i}-{n}_{j})}^{2}/{sigma }_{{{{{rm{C}}}}}}^{2}-tfrac{1}{4}{({n}_{i}-{n}_{j})}^{4}/{gamma }_{{{{{rm{C}}}}}}^{4}right).$$

(2e)

To ensure our results are robust when the functions above deviate from Gaussian shapes, we allow platykurtic functions in Eqs. (2c)(2e): specifically, the parameters ({gamma }_{{{{{rm{p}}}}}}), ({gamma }_{{{{{rm{c}}}}}}), ({gamma }_{{{{{rm{P}}}}}}), and ({gamma }_{{{{{rm{C}}}}}}) scale the quartic terms in the exponents above and hence the extent to which those functions are platykurtic, i.e., deviate from Gaussian shapes in the direction of more box-like shapes. Even slight degrees of platykurtosis are known to overcome the historically often overlooked structural instability caused by purely Gaussian functions in models of trait-mediated competition and thereby suffice to enable the ecologically and evolutionarily stable coexistence of phenotypically differentiated discrete species (e.g., refs. 65,66).

In summary, the combined effects of body size and ecological niche on predation and interference competition are given by the products (p({r}_{i},{r}_{j})P({n}_{i},{n}_{j})) and (c({r}_{i},{r}_{j})C({n}_{i},{n}_{j})), respectively, as shown in Eqs. (1).

The evolutionary dynamics of the adaptive traits are determined by the corresponding selection pressures (e.g., refs. 44,45). Writing (F({N;}{x}_{0},ldots ,{x}_{N};{s}_{0},ldots ,{s}_{N};{n}_{0},ldots ,{n}_{N})) for the right-hand side of Eq. (1a), we define the invasion fitness of an initially rare population with trait values ({s}^{{prime} }) and ({n{{hbox{'}}}}) in a community comprising the autotropic basal resource and (N) resident heterotrophic species with population densities ({x}_{0},ldots ,{x}_{N}) and trait values ({s}_{0},ldots ,{s}_{N}) and ({n}_{0},ldots ,{n}_{N}) as

$$f(N{{{{{rm{;}}}}}}x,s,n{{{{{rm{;}}}}}}{s}^{{prime}},{n}^{{prime}} )=mathop{{{{{mathrm{lim}}}}}}limits_{{x}^{{prime} }to 0+}Fleft(N+1{{{{{rm{;}}}}}}{x}_{0},ldots ,{x}_{N},{x}^{{prime} }{{{{{rm{;}}}}}}{s}_{0},ldots ,{s}_{N},{s}^{{prime} }{{{{{rm{;}}}}}}{n}_{0},ldots ,{n}_{N},{n}^{{prime} }right),$$

(3a)

where (x=({x}_{0},ldots ,{x}_{N})), (s=({s}_{0},ldots ,{s}_{N})), and (n=({n}_{0},ldots ,{n}_{N})).

We solve the (N+1) demographic equations in Eqs. (1) alongside (2N) evolutionary equations, one for each trait in each species,

$${dot{s}}_{i}={varepsilon }_{{{{{{rm{s}}}}}}}{left.frac{partial fleft(N{{{{{rm{;}}}}}}x,s,n{{{{{rm{;}}}}}}s^{prime} ,n^{prime} right)}{partial s^{prime} }right|}_{{s}^{{prime} }={s}_{i},{n}^{{prime} }={n}_{i}}$$

(3b)

and

$${dot{n}}_{i}={varepsilon }_{{{{{{rm{n}}}}}}}{left.frac{partial fleft(N{{{{{rm{;}}}}}}x,s,n{{{{{rm{;}}}}}}s^{prime} ,n^{prime} right)}{partial n^{prime} }right|}_{{s}^{{prime} }={s}_{i},{n}^{{prime} }={n}_{i}},$$

(3c)

where ({varepsilon }_{{{{{{rm{s}}}}}}}) and ({varepsilon }_{{{{{{rm{n}}}}}}}) scale the rates of evolutionary change. We assume ({varepsilon }_{{{{{{rm{s}}}}}}}) and ({varepsilon }_{{{{{{rm{n}}}}}}}) to be so small that body sizes and ecological niches are evolving slowly relative to the demographics dynamics.

Evolution of the adaptive traits under directional selection proceeds according to Eqs. (3) until a local fitness minimum is encountered in one or more of the heterotrophic species and selection thus turns disruptive. Specifically, we test whether the magnitudes of the selection pressures, i.e., of the derivatives in Eqs. (3b) and (3c), fall below a prescribed threshold for both adaptive traits. If and when the underlying extremum in a species invasion-fitness landscape given by Eq. (3a) happens to be a minimum, the species is replaced with two species with trait values shifted a fixed distance toward either side of the fitness minimum along the direction of steepest increase (i.e., highest curvature) of invasion fitness, in a process intended to mimic ecological speciation67,68.

Further information on research design is available in theNature Portfolio Reporting Summary linked to this article.

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Ecological determinants of Cope's rule and its inverse | Communications Biology - Nature.com

Biology

New Evolution Theory Explains Why Animals Shrink Over Time – SciTechDaily

A recent study uncovers the factors influencing animal size changes over time, identifying three evolutionary patterns based on competition and environmental pressures, providing clarity on the inconsistencies in fossil records. Credit: SciTechDaily.com

New research reveals key factors behind the changing sizes of certain animals over time, challenging traditional evolutionary theories with its findings on species size variations.

The mystery behind why Alaskan horses, cryptodiran turtles, and island lizards shrunk over time may have been solved in a new study.

The new theoretical research proposes that animal size over time depends on two key ecological factors: the intensity of direct competition for resources between species, and the risk of extinction from the environment.

Using computer models simulating evolution, the study, published today (Thursday, January 18) in the journal Communications Biology, identifies why some species gradually get smaller, as indicated by fossil records.

Dr. Shovonlal Roy, an ecosystem modeler from the University of Reading who led the research, said: Just like how we try to adapt to hot or cold weather depending on where we live, our research shows animal size can get bigger or smaller over long periods depending on the habitat or environment.

In places and times where theres lots of competition between different species for food and shelter, animal sizes often get smaller as the species spread out and adapt to the distribution of resources and competitors. For example, small horses that lived in Alaska during the Ice Age rapidly shrank due to changes in the climate and vegetation.

Where direct competition is less, sizes tend to get bigger, even though being really big and few in number can make animals more vulnerable to dying out such as what happened with the dinosaurs.

Changes in ecological factors help explain why fossil records shows such confusing mixes of size evolution patterns, with some lineages shrinking over time and others growing.

The research team carried out their study by challenging the contradictions fossil evidence posed to Copes rule. Copes rule refers to the tendency for certain animal groups to evolve larger body sizes over thousands and millions of years. The rule is named after Edward Cope, a 19th-century paleontologist who was credited to have first noticed this pattern in the fossil record. For example, early horse ancestors were small dog-sized animals that increased in size over evolutionary time, ultimately producing the modern horse.

However, fossil evidence shows remarkably conflicting trends, with increased size in some groups but decreased size in others.

Using computer models simulating evolution, the study identified three distinct patterns of body-size change emerging under different conditions:

Reference: Ecological determinants of Copes rule and its inverse 18 January 2024, Communications Biology. DOI: 10.1038/s42003-023-05375-z

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New Evolution Theory Explains Why Animals Shrink Over Time - SciTechDaily

Biology

Gustavus BMB Major Earns Prestigious Accreditation – The American Society of Biochemistry and Molecular Biology … – Gustavus Adolphus College

Gustavus is one of only nine colleges in Minnesota to receive the ASBMB distinction.

The Gustavus Biochemistry and Molecular Biology (BMB) Program recently learned that it has been accredited by the American Society of Biochemistry and Molecular Biology (ASBMB), the fields professional organization. ASBMB accreditation is a national distinction, rarely bestowed, that will be recognized by graduateand professional schools and science industry employers as confirmation that Gustavus BMB graduates are thoroughly prepared for professional success in the field.

Gustavus already is the top-ranked liberal arts college in Minnesota to offer a BMB major. The College is one of about 100 schools in the U.S. to secure ASBMB accreditation, and one of just nine in Minnesota. BMB faculty members Jeff Dahlseid 90, Heather Haemig, and Janie Frandsen applied for accreditation in fall 2023 to bolster an already well-established program. Gustavus has had up to 20 BMB majors per year since its establishment in the early-1990s, graduating about 14 such majors per year in the past half-decade, making it one of our more popular majors.

Nationwide, schools that offer this major will often offer it as a second major within a biology department, or a second major within the chemistry department, said Dahlseid, the BMB program director. Ours is jointly sponsored by our Biology and Chemistry departments. It doesnt necessarily lean one way or the other, so we better support students with interests anywhere along that continuum.

This flexibility and range of options prepares Gustavus BMB students for career options including teaching, research, medicine, and other industry-specific fields that involve critical thinking and leadership. The accreditation reinforces how our students receive lots of hands-on learning with inquiry-oriented pedagogy, so that students are exceptionally well prepared to take next steps in industry or in graduate schools, where theyll actually need to apply the science theyve learned to real-world problems, Dahlseid said.

The ASBMB accreditation will run through 2030 and was granted because the organization affirmed Gustavus BMBs accomplishments in and commitments to the following areas, among others:

The really cool thing to me about the accreditation is that we didnt do anything different or new in recent years to get it, said Haemig, senior continuing assistant professor in BMB. This doesnt really change anything for those students that have already gone through the program, because we were doing all those things when they were here.

Gustavus has long been one of the only liberal arts colleges in the state of Minnesota to offer a full major in biochemistry and molecular biology, which this accreditation reflects. The fact that the program were offering has been recognized by the external society for the field demonstrates that the education our students are getting in the discipline is robust, said Frandsen, assistant professor in BMB.

She added that even though the BMB major has more course requirements than many other majors at the College, that doesnt keep BMB Gusties from participating in all aspects of Gustavus life in and out of the classroom. If anything, BMB students are more involved than the average Gustavus student, she said. Theyre athletes or in music. They have minors or second majors. Theyre doing it all.

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Media Contact: Director of Media Relations and Internal Communication Luc Hatlestad luch@gustavus.edu 507-933-7510

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Gustavus BMB Major Earns Prestigious Accreditation - The American Society of Biochemistry and Molecular Biology ... - Gustavus Adolphus College

Biology

SARS-CoV-2 biology and host interactions – Nature.com

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