Newly identified small-RNA pathway defends genome against the enemy within
Reproductive cells, such as an egg and sperm, join to form stem cells that can mature into any tissue type. But how do reproductive cells arise? We humans are born with all of the reproductive cells that ...
Long-held assumption about emergence of new species questioned
Darwin referred to the origin of species as "that mystery of mysteries," and even today, more than 150 years later, evolutionary biologists cannot fully explain how new animals and plants arise.
Study: Marmoset success with twin gestation
(Phys.org) —How can the tiny marmoset – a New World monkey – regularly successfully bear twins and sometimes triplets and quadruplets when much larger humans often face a difficult pregnancy and delivery?
Study finds that the slower 'eusocial' system in nature offers high risks, high rewards
It's a cliché to say it takes a village to raise a child, but it's a cliché some creatures have taken to heart.
Resurrecting ancient proteins, team finds just two mutations set stage for evolution of modern hormone signaling
Evolution, it seems, sometimes jumps instead of crawls. A research team led by a University of Chicago scientist has discovered two key mutations that sparked a hormonal revolution 500 million years ago.
Two Y genes can replace the entire Y chromosome for assisted reproduction in mice
The Y chromosome is a symbol of maleness, present only in males and encoding genes important for male reproduction. But live mouse offspring can be generated with assisted reproduction using germ cells from ...
Sperm wars: Evolutionary biologist compiles international special issue on sperm competition
Why do male animals need millions of sperms every day in order to reproduce? And why are there two sexes anyway? These and related questions are the topic of the latest issue of the research journal Molecular Hu ...
Study sheds light on 'reinforcement' in wildflowers
Plants or animals using color to attract a mate is fairly common in nature, but for Phlox drummondii, a wildflower commonly known as Drummond's phlox, just the opposite is true.
Researchers test whether Red Queen hypothesis makes species resilient
In Lewis Carroll's 1871 classic novel Through the Looking Glass, the Red Queen tells Alice: "Now, here, you see, it takes all the running you can do, to keep in the same place."
That pregnant feeling makes a fly start nesting
Across the animal kingdom, it's not uncommon for pregnancy to change an expectant mom's behavior. Even female flies have their own rudimentary way of "nesting," which appears to be brought on by the stretch ...
Viruses impaired if their targets have diverse genes
When a viral infection spread through five genetically identical mice in a row, the virus replicated faster and became more virulent or severe. But when the infection spread one-by-one through five genetically ...
How plants may be evolving to the lack of bees
Plants which used to have two types of male reproductive organs – to increase their chances for fertilisation – are reverting back to one type. And in some cases, they are becoming self-fertilising.
Outdated assumptions make evolutionary researchers ignore female genitalia
(Phys.org) —Animal genitalia are structurally diverse organs that can evolve rapidly under powerful selective forces exerted by the peculiarities of sexual reproduction. An overarching review of the existing ...
Scientists map reproductive system's evolution as dinosaurs gave rise to birds
As winged dinosaurs underwent a series of evolutionary changes during the transition into Aves, or birds, one pivotal transformation was the appearance of a single-ovary reproductive system. "The most widely ...