Category Archives: speciation

My short intro to the genetics of speciation

UPDATE: If you want a pdf of my article, which seems to be behind a paywall, just inquire judiciously. _________________   The journal Molecular Ecology is producing a special issue on “Sex chromosomes and speciation”, which will contain about 17 papers. Some of these have already been published online, and though there’s not yet a […]

“Reverse speciation” (fusion of species) in ravens

At least a dozen readers have called my attention to a new paper in Nature Communications by Anna M. Kearns et al. (reference at bottom, pdf here), supposedly showing “reverse speciation” in ravens. The paper has received a lot of public attention because it claims to show that two distinct species of ravens have fused back […]

A “parthenogenetic” crayfish reproduces without sex: is it a new species?

There must have been more than a dozen readers who sent me links to the article below by Carl Zimmer in the New York Times (thanks, all!). I skimmed it but was more interested in the published scientific papers about the marbled crayfish. This “species”, if you can call it that (see more below), is […]

Hybrid speciation in Galápagos finches

I’ll take “speciation” in this post, as do all the authors involved, to mean “the origin of reproductive barriers between populations that live in the same area, preventing them from either cross-mating or producing fertile hybrids if they do.” Most biologists think that speciation—the acquisition of these barriers—requires a prolonged period of geographical isolation between […]

Defining species: a new but problematic species concept

A few days ago I was interviewed by Eva Botkin-Kowacki, a science writer for the Christian Science Monitor. She wanted to discuss a new paper on speciation in birds, a commentary published in The Auk by Geoffrey E. Hill of Auburn University: “The mitonuclear compatibility species concept” (free download, reference at bottom). She also interviewed several other […]

How (and how fast) do new species form?

Most evolutionists think that speciation, which we see as the origin of a new group whose members are unable to produce fertile hybrids with other such groups (but whose members are interfertile with each other) occurs in the following way. Populations of a single species become geographically isolated by the interposition of geographic barriers like mountains, deserts, water, […]

PBS: How many species of giraffes are there?

A while back I discussed a paper in Current Biology by Julian Fennessy et al. . That paper used genetic analysis (the total genetic divergence among groups) to claim that there are actually four species of giraffe instead of a single species with nine subspecies. Using the Biological Species Concept (BSC), however, I argued that there […]

The politics of speciation

From reader Pliny the in Between’s newly renamed site, The Far Corner Cafe, we have a cartoon called “If you catch my genetic drift.” Click to enlarge. I would never mate with a Republican!

12 days of evolution. #5: Have we seen new species arise?

This is a video after my own heart, since it’s about speciation: the splitting of a single lineage into two or more lineages unable to exchange genes. The question at hand, since this series—put together by PBS and “It’s Okay to be Smart”—is a long refutation of common creationist arguments, is this one: “Can we […]

The “coywolf”: a new species of canid?

At least three readers have pointed me to articles, one in The Economist and the other in Raw Story, arguing that a new species of canid, the “coywolf” (also called a “wolfote”) is emerging before our eyes as wolves (Canis lupus), domestic dogs, and coyotes (Canis latrans) all hybridize to form a distinct entity. Such “hybrid […]