Man or woman? Male or female?

Modern sociological woo about gender aside, in humans and other mammals, the difference between the sexes depends on one single element of the genome: the Y chromosome. It is present only in males, where the two sexual chromosomes are X and Y, whereas women have two X chromosomes. Thus, the Y is ultimately responsible for all the morphological and physiological differences between males and females.

We are all familiar with the Mafia. In China, it is the Triads, in Italy it is La Cosa Nostra. You pay for protection or disaster is sure to befall you.

It happens in the bird world too, according to a new report. A bird will lay an egg in your home and you will raise the hatchling or pay the price. Throw the little parasite out and an accident will befall your nest.

It is a child-rearing strategy, but is it an effective one? Evolutionary biologist Amotz Zahavi postulated the mafia hypothesis back in 1979 and it has been contentious ever since. Critics argue that the retaliation gives the parasites no advantage, carrying high costs instead.

Evolutionary biologists created a mathematical model to find out. 
Without knowing it, organisms search for the next “winning” strategy in evolution. Mutation plays a key role in the evolution of new, and sometimes successful, traits. It's a lot like rock-paper-scissors - roshambo.(1)

A new paper suggests that genes evolve more rapidly in species containing germ plasm, which
challenges a long held belief about the way certain species of vertebrates evolved. 

The results came about as the researchers put to the test a novel theory that early developmental events dramatically alter the vertebrate body plan and the way evolution proceeds. 

Fruit flies are secretly harboring the biochemistry needed to glow in the dark —otherwise known as bioluminescence - according to a paper in 
Proceedings of the National Academy of Sciences. 

Harvard evolutionary biologist Professor David Haig believes that infants that wake frequently at night to breastfeed are delaying the resumption of the mother's ovulation and therefore preventing the birth of a sibling with whom they would have to compete.

In a new paper, researchers writing in Current Biology show how lactase persistence variants tell the story about the ancestry of the Khoe people in southern Africa and that their pastoralist practices were probably brought to southern Africa by a small group of migrants from eastern Africa.

Although Neanderthals are extinct but fragments of their genomes persist in modern humans.

 These shared regions are unevenly distributed across the genome and some regions are particularly enriched with Neanderthal variants. An international team of researchers led by Philipp Khaitovich of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the CAS-MPG Partner Institute for Computational Biology in Shanghai, China, have found that DNA sequences shared between modern humans and Neanderthals are specifically enriched in genes involved in the metabolic breakdown of lipids.

Why zebras have black and white stripes is a long-standind puzzle of evolution.

To find out, the researchers behind a Nature Communications paper mapped the geographic distributions of the seven different species of zebras, horses and asses, and of their subspecies, noting the thickness, locations, and intensity of their stripes on several parts of their bodies. Their next step was to compare these animals' geographic ranges with different variables, including woodland areas, ranges of large predators, temperature, and the geographic distribution of glossinid (tsetse flies) and tabanid (horseflies) biting flies.

They then examined where the striped animals and these variables overlapped.

Genghis Khan is famous in evolution because a giant chunk of the world carries is DNA. A recent story of brown bears shows that males roam much greater distances than females, and mating is part of the agenda.