Anatomic variation, as a biological process, refers to the genetically and developmentally determined divergence in the form, size, position, or number of anatomical structures among individuals of the same species. It arises from coordinated molecular, cellular, and morphogenetic events during embryogenesis and postnatal growth, including differential gene expression, signaling gradients, and tissue patterning mechanisms that modulate organogenesis and body plan architecture. These variations are typically nonpathological and occur within a spectrum of species-typical phenotypes, contributing to phenotypic diversity, influencing physiological function, and modulating susceptibility to disease, surgical risk, and outcomes of diagnostic and interventional procedures.
In the animal kingdom, penises can be spiked, split, corkscrewed—even detachable. They're one of the most diverse structures in biology. The human penis is so uniform, it's an anatomical outlier. Understanding why penises ...
Plants & Animals
Nov 28, 2025
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130
Fish species living in the deep sea feature a surprisingly large range of body shapes that evolved in different ways and at different rates depending on where the fishes live in the ocean, new research shows.
Evolution
Nov 13, 2025
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651
Every human face is unique, allowing us to distinguish between individuals. We know little about how facial features are encoded in our DNA, but we may be able to learn more about how our faces develop by looking at our ancient ...
Evolution
Nov 10, 2025
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159
As a Ph.D. student, I wanted to understand the evolution of individual differences in fruit fly behavior—the building blocks of personality. My experiments involved measuring how my tiny subjects acted in a maze.
Evolution
Oct 16, 2025
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81
A study of elephants, giraffes and other wildlife in Namibia's Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across ...
Ecology
Oct 15, 2025
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22
Sexual size differences are widespread in biology, yet the "how" behind them often remains vague. We asked a concrete question in a classic model organism: when female flies are larger than males, do individual organs achieve ...
Four-limbed vertebrates, known as tetrapods, have two enlarged areas in their spinal cords. The two enlargements have a correlation with the forelimbs and hind limbs, respectively. These enlargements are thought to be caused ...
Plants & Animals
Oct 7, 2025
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25
Around the world, women on average live longer than men. This striking pattern holds true across nearly all countries and historical time periods. Although the gap between the sexes has narrowed in some countries due to medical ...
Plants & Animals
Oct 1, 2025
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167
Heterostyly, a floral polymorphism where a species produces two or three distinct flower types with reciprocal arrangements of stigmas and anthers, boosts pollination accuracy, reduces sexual interference, and encourages ...
Plants & Animals
Sep 18, 2025
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23
At Cornell, Dawn Chen was counting sperm stored in a pair of organs called spermathecae in female fruit flies, fully expecting the counts to be roughly the same. The two spermathecae, which store and release sperm after a ...
Plants & Animals
Sep 16, 2025
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