Evolution refers to the observed changes in successive generations of biological organisms due to heritable components (genes and DNA). Charles Darwin proposed a major mechanism of evolution: natural selection.
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Evolutionary origin and exogenous cues of ~28 day infradian rhythm?
The most obvious example of an approximately monthly biological cycle is the human menstrual cycle. My questions are the following:
Is it known when and where this cycle or one like it arose?
What ...
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Are there any structures in mammals that are used only by males?
There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
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140 views
Did we first have swimming birds or flying birds?
Looking at the swimming birds building nests just across my garden, I suddenly wondered how evolution came to swimming birds and whether flying birds started swimming or whether swimming bird like ...
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3answers
394 views
What is the most difficult feature to explain evolutionarily? [closed]
I wonder what are examples of organs/structures/behaviours/cooperation that evolutionary biologists themselves find most difficult to explain -- to explain how they could appear evolutionarily -- ...
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How did the human brain evolve?
A common question posed is, "how did the eye evolve?", because the eye is so complex. However, this has been answered rather clearly and there are several examples around the world of animals in ...
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163 views
How do we know that dinosaurs were related to lizards and/or birds?
Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
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What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?
I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage?
For example, consider a ...
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Is there a dominant gene for right-handedness?
Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular ...
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Can species back-evolve?
One of the tenets of Darwin's theory is the survival of the fittest, ie adaptation of features that allow a species to adapt better to its surrounding environment. I am wondering that given the right ...
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How did viruses come to be?
My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any ...
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189 views
How To Avoid Macro-Evolution Confusion? [closed]
I regularly encounter students who believe humans came from amoebas and when asked why they often say Macro-Evolution has been scientifically proven.
Macro-evolution is defined as evolution at or ...
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111 views
What do we know about LUCA?
All life on Earth (bacteria, archaea, eukarya) is thought to have evolved from a common ancestor, or last universal common ancestor (LUCA). What do we know about the characteristics of LUCA based upon ...
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134 views
What evolutionary mechanism caused felines to develop purring?
And why can some felines roar while others meow?
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Is it the case that all changes in phenotype during life are not inheritable?
This came up in a talk with a friend. I wanted to clear this doubt. I've read about it before and did again after her remark (my thoughts didn't change: her concept is Lamarck's, not Darwin's), but ...
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Are there differences in DNA between humans of today and humans from 2000 years ago?
Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago?
And if there are significant differences, do they result in significant ...
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320 views
Do men have more extreme variations than women?
This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences
I was reading this article which I found interesting. It is not supported with ...
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283 views
Did human hairs actually evolve from scales?
What is the evolution of hairs? Did they evolve from scales?
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What is the closest species to humans in animal kingdom?
I presumed chimpanzees were the closest relatives of us. However, after watching this TED Talk, it seems bonobos are closer to us both in skeleton and behavioral similarity than chimpanzees. I once ...
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What are the evolutionary niches differentiating an apple from a pear?
So, as far as I understand (basic) evolutionary theories, diversity is generated by "niching." That is, if there is an environmental factor that hasn't been fully used by any species to "profit" off, ...
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195 views
Why do pandas have a high probability of giving birth to twins?
According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
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Good source that explains the evolution of single-celled organisms “from scratch”
Are there any books or sites that detail, step-by-step, the evolution of the first single-celled organisms (bacteria, archaea) from a Miller-Urey-like beginning? That is, assumes only amino acids, ...
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330 views
Why are there nail growth differences between humans and other mammals?
When a cat is growing, his nails are growing with him to some extent. A grown cat has a fixed nail length that is not extending.
By contrast, human finger nails just keep on growing, so we have to ...
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2answers
263 views
Is there evidence that some non-human species perform sexual selection based primarily on intelligence? How do they do this?
I'm a biology amateur, but it seems like sexual selection is almost always performed based on physical characteristics, the outcome of physical contests, or some sort elaborate courtship. But do any ...
9
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425 views
Why do some plant species have lobed leaves, while similar species in the same habitat don't?
Some plants have lobed leaves, like the English oak (Quercus robur), while other plants growing the same deciduous woodland habitats, and very often growing alongside oaks, such as the European beech ...
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Why did the process of sleep evolve in many animals? What is its evolutionary advantage?
The process of sleep seems to be very disadvantageous to an organism as it is extremely vulnerable to predation for several hours at a time. Why is sleep necessary in so many animals? What advantage ...
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327 views
Why would stablising selection ever happen?
If the aim of evolution is to allow an organism to better compete against rivals, why would stabilizing selection ever happen? If you're not selecting the most highly adapted competitors at either end ...
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What is the benefit for cells having the ATP production regulated in mitochondria compared to being from the nucleus?
Mitochondria have their own DNA and appear to be loosely connected to the nucleus and it role.
Why are the functions of mitochondria not in the nucleus? Why doesn't the nucleus control the ...
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Did researchers evolve multicellular yeast or did they just turn on multicellularity?
In this new paper "Experimental evolution of multicellularity" found via Ars Technica the researchers describe having developed multicellularity and apoptosis within 60 days from a unicellular yeast ...
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Abiogenesis: Beyond the research journals as a lead in to discussions on evolution
I just came across this abstract:
Aminoacyl-tRNA synthetases (aaRSs) are responsible for creating the pool of correctly charged aminoacyl-tRNAs that are
necessary for the translation of genetic ...
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Could an organism theoretically produce a metamaterial-like structure? [closed]
I'm curious to know if this is physically feasible because during my reading up on synthetic biology and just general research i realise that life is capable of producing some exquisitely complex ...
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Are there any pre-Holocene venomous animals?
The novel (and subsequently movie) Jurassic Park featured a dinosaur called Dilophosaurus, that was purported to be venomous and had an ability similar to that of the extant spitting cobra. ...
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Do large animals often evolve into smaller animals?
There are several examples where the largest animals were killed off preferentially due to a major ecological shift:
The KT extinction event
The Holocene extinction, as well as the major megafauna ...
