sexual selection
cagapakis | May 31, 2010I love this quote from the XKCD blog:
The role of gender in society is the most complicated thing I've ever spent a lot of time learning about, and I've spent a lot of time learning about quantum mechanics.
Many scientists try very hard to de-emphasize this complexity, trying to reduce "human nature" down to parts and genes and behaviors that can be explained by evolutionary mechanisms, by hormones, by genetics. It's not nature vs. nurture and it's not just male and female, it's nature and nurture and infinite variations along a culturally and biologically mediated gender continuum. By…
grrlscientist | March 29, 2010tags: evolution, evolutionary biology, behavioral ecology, animal behavior, molecular ecology, parental care, mating systems, monogamy, sexual selection, frogs, poison dart frogs, Dendrobatidae, Ranitomeya, researchblogging.org,peer-reviewed research, peer-reviewed paper, journal club
Peruvian mimic poison frog, Ranitomeya imitator.
Image: Jason Brown [larger view]
To know the breeding system is to know the genetic architecture of a species.
To know the evolution of a breeding system is to know how evolution works ..
~ Lewis & Crowe, Evolution (1955)
Genetic tests have revealed the…
laelaps | March 19, 2010
At almost every aquarium I have ever visited with a seahorse exhibit, the plaque in front of the tank says the same thing: in seahorses and their relatives, males, not females, carry the babies. It is always interesting to watch the reactions of visitors to this curious fact. Adult men, for instance, sometimes seem unsettled by the thought of male pregnancy, but the reproductive reversal among the fish is often seen as kinda cute ("How sweet. A fishy dad taking care of his kids!"). As shown by a study by Kimberly Paczolt and Adam Jones published this week in Nature, however, there can be…
razib | December 7, 2009
Well, I don't quite know about that, but that's the sort of take-away from a new paper in PLoS Biology which looks at the downsides of female attractiveness. A Cost of Sexual Attractiveness to High-Fitness Females:
Adaptive mate choice by females is an important component of sexual selection in many species. The evolutionary consequences of male mate preferences, however, have received relatively little study, especially in the context of sexual conflict, where males often harm their mates. Here, we describe a new and counterintuitive cost of sexual selection in species with both male mate…
sb admin | May 8, 2009
Two male Rhagoletis walnut flies joust on an artificial walnut in a lab cage at the University of Arizona. What's an artificial walnut? It's a painted ping pong ball. As long as the ball is the right color and shape, the flies apparently don't mind.
Biologist Jeremy Davis uses these flies to study the interaction between fruit quality and fly behavioral ecology.
Of course, for the flies it's all about access to females.
Technical details.
top photo: Lens: Canon MP-E 65mm 1-5x macro lens
Body: Canon EOS 20D dSLR
Flash: Canon 550EX flash, indirect
Settings: ISO 200, f/11, 1/200 sec
middle…
razib | April 29, 2009
In the wake of Predictably Irrational, check out Tyler Cowen's endorsement of Geoffrey Miller's new book, Spent: Sex, Evolution, and Consumer Behavior. Miller is a good writer, so I'm assuming it will be a page-turner, but he does tend to be "provocative" in all the best & worst ways when it comes to popular science. Evolutionary psychologists have a tendency to make everything about sex & status, but within the field it seems Miller does come off as the "pimp daddy" always talking about the "bling" and "b**tches" as the raison d'être.
razib | April 8, 2009Women May Be Sniffing Out Biologically-relevant Information From Underarm Sweat:
Sniffed alone, the underarm odors smelled equally strong to men and women. When fragrance was introduced, only two of 32 scents successfully blocked underarm odor when women were doing the smelling; in contrast, 19 fragrances significantly reduced the strength of underarm odor for men.
...
Not only were women better smellers the men, but male odors were harder to block than female odors. Even though underarm odors from the two sexes didn't differ in how strong they smelled, only
So women have a better sense of…
razib | March 25, 2009Nick Wade in The New York Times has a piece on a review on the relationships between male competition, signaling and sexual selection. If the topic interests you I strongly recommend Animal Signals, John Maynard Smith's last book.
laelaps | February 5, 2008I didn't think it was going to air so early in the year, but apparently David Attenborough's latest program (and last in the "Life of..." series), Life in Cold Blood, is now airing in the UK. The Telegraph recently published an article about the joy of watching Attenborough's documentaries, and I was able to find one clip from the show already online. It features the Panamanian golden frog (Atelopus zeteki), a species that is critically endangered if not already extinct in the wild;
Previously it had been said that this was going to be Attenborough's last project, but according to the…
grrlscientist | December 17, 2007tags: researchblogging.org, blue tits, Cyanistes caeruleus, Parus caeruleus, sexual selection, mate choice, ornithology, female coloration, reproduction, maternal quality, evolution, birds, ornithology
In many bird species, the females are brightly colored, just as the males are, but the evolutionary reasons for brightly colored females is unclear. According to one hypothesis, because males and females share the same genome, their traits are similar. However, according to another hypothesis, there may also be selective pressures on females, just as there are on males, to develop brightly…
laelaps | November 20, 2007Sexual dimorphism in organisms is nothing new; it has long been known that in certain species one sex is often larger, flashier, or somehow markedly different than the other. In some species like the Indian Peafowl (Pavo cristatus), the mail carries a brightly colored train that is used to advertise to prospective female mates, while in the deep-sea anglerfish Suborder Ceratioidea the males are absolutely minuscule when compared to the females, fusing to the bodies of the larger sex and ultimately becoming little more than a sperm supply. Such differences are contrasted with the almost non-…
grrlscientist | August 31, 2007tags: researchblogging.org, splendid fairy-wren, Malurus splendens,sexual dichromatism, evolution, behavior, promiscuity, social monogamy
Male splendid fairy-wren, Malurus splendens.
Image: Pete Morris (Surfbirds.com). [screensaver size]
Everyone is familiar with sexual dichromatism in birds; you know, the gorgeous, colorful male who is paired with the drab female or two. It has been observed in birds that, when males and females differ dramatically in appearance, the females are preferentially mating with a few "pretty boys"; those that have elaborate plumage colors or ornamentation. As…