Wednesday, January 1, 2014

Carnival of Evolution, No. 67 — Wallace centenary edition

Charles Darwin's Tree of Life metaphor (from 1859) has become world-famous. However, Alfred Russel Wallace, who independently developed the idea of evolution by means of natural selection, had already used a very similar image in 1855, when he noted: "the analogy of a branching tree [is] the best mode of representing the natural arrangement of species ... a complicated branching of the lines of affinity, as intricate as the twigs of a gnarled oak ... we have only fragments of this vast system, the stem and main branches being represented by extinct species of which we have no knowledge, while a vast mass of limbs and boughs and minute twigs and scattered leaves is what we have to place in order, and determine the true position each originally occupied with regard to the others".

This past year has been one in which many people commemorated the death of Wallace (1823-1913), and so it seems appropriate to join them for the final summary of 2013's posts at the Carnival of Evolution.

Wallace spent 1848-1852 collecting in the Amazon, and 1854-1862 doing the same in South-East Asia. He is best known today for his studies of biogeography, but he also worked on what we now call environmental issues, and even what is now known as exobiology. More controversially, he also involved himself in social criticism, and atheistic spiritualism. At his death, he was as well known as any living biologist; but since then he has sadly been eclipsed by Darwin.

This month's blog posts

Wallace was interested in origins, of course, so we can start the list of evolution posts with that topic.

Darren Naish at Tetrapod Zoology discussed a new species of perissodactyl from the Amazon (A new living species of large mammal: hello, Tapirus kabomani) (submitted by Donald Prothero). New mammal species are rather rare these days, but Wallace would not have been surprised to find them in the Amazon.

At the Panda's Thumb, Wilson Sayres asked: Why sequence the manatee genome? (submitted by Ryan Gregory). In spite of being aquatic mammals, manatees are more closely related to elephants than they are to dolphins or whales. Gert Korthof then took us to the origin of life (New Szostak protocell is closest approximation to origin of life and Darwinian evolution so far), discussing the creation of a prebiotically plausible protocell, consisting of a fatty acid vesicle in which RNA replication occurs autonomously without the help of enzymes.

Kathy Orlinsky at The Stochastic Scientist then takes us to the origin of genetic variation, noting that for mitochondria DNA mutations might not be so random after all.


Wallace studied adaptations, among other things, so we can now proceed on to that topic.

GrrlScientist was formerly one of the mainstays of the Carnival of Evolution, but she then drifted off into natural-history blogging, instead. However, this month she reported on a study of hummingbird species living at high altitudes (How do hummingbirds thrive in the Andes?). They have independently evolved hemoglobin with enhanced oxygen-binding properties, so they can thrive in oxygen-poor environments.

Ed Yong at Not Exactly Rocket Science considered the evolution of the two of the oddest mammals, the platypus (How the platypus and a quarter of fishes lost their stomachs) and the koala (Organ helps koalas bellow at elephant pitch).

Tim Eisele at The Backyard Arthropod Project talked about the options available for getting yourself through the winter when you are a living organism (Winter is the enemy).

At Eco-Evo Evo-Eco, Steven Brady contemplated why wood frog populations seem locally maladapted to roads (Homage to the Island of Misfit Toys) (submitted by Ben Haller), and Andrew Hendry considered the question of whether adaptation is driven by many genes of small effect or by a few genes of large effect (Epic wrap battles of Christmas).

Wallace's main collecting interest was beetles

Processes were at the heart of Wallace's evidence for evolution, so we should look at this topic, too.

Caroline Tucker at The EEB & Flow looked at an example (Ecological processes may diffuse through evolutionary time: an example from Equidae) of how patterns of trait divergence and adaptive radiation can evolve as a result of diffusion evolution, rather than from a single strong ecological pressure (submitted by Bradly Alicea).

At Synthetic Daisies, Bradly Alicea examined the nonlinear evolutionary dynamics of Mexican cavefish (Dragons, sandpiles, and cavefish: an evolutionary inquiry), considering both the Sandpile and the Dragon King statistical models for the developmental changes that made them eyeless.

Kim Gilbert at The Molecular Ecologist asked the question: How prevalent are non-overlapping generations?, which is of obvious importance for evolutionary modeling, and found that there is no known answer.

At The Genealogical World of Phylogenetic Networks, David Morrison asked a phylogenetic question: Is rate variation among lineages actually due to reticulation? He decided that it might be, but for most studies it is simply an untested assumption that it isn't.


Selection involving groups was a bit out of Wallace's line, but it is prominent these days.

At Evolution in Structured Populations, Charles Goodnight noted that kin selection can be useful for developing an intuitive or qualitative grasp of social evolution, but for many reasons it fails when it is applied to the real world (Now I know I am "El Lobo Solitario"). He then considered the phenotypic view of evolution, by assessing the adaptive role of religion in providing cohesion in societies (Group selection and religion) (submitted by Bjørn Østman).

Wallace's global biogeographical regions

Now we come to those posts about the broad range of applications of evolutionary ideas.

Sarah Bodbyl at the BEACON blog asked about whether plants experiencing rapid loss of their pollinators are able to adapt and maintain viable populations by increasing their ability to reproduce without pollinators (Mating system evolution).

At The Mermaid's Tale, Anne Buchanan noted that genes associated with domestication and diversification have been identified with fine-mapping or genome-wide association studies, thus distinguishing artificial selection from natural selection (What domestication can and can't tell us about evolution). Then, Ken Weiss asked: "Every trait is due to natural selection!" .... often said, but is it true? This is belief in a form of very strong determinism, which he investigates in relation to the human thumb.

Carl Zimmer at The Loom pointed out that one of the best places to survey the sloppy creativity of evolution is inside your own nose (The smell of evolution).

Noah Reid at Nothing in Biology Makes Sense highlighted one of the more popular topics of the news, blog and twitter world in late November, which concerned a proposed phylogeny of the well-known folk tale about Little Red Riding Hood (Learn the origins of fairytales with this one weird trick!). However, The Genealogical World of Phylogenetic Networks has countered with a post about The phylogenetics of Little Red Riding Hood, in which it is shown that studying the evolution of folk tales requires knowledge of the time direction of evolutionary change — and it appears that the proposed phylogeny might be wrong.


Finally, here are some miscellaneous blog posts about evolution and blogging.

PZ Myers, the grumpy old man at Pharyngula, critiqued a paper on the human brain that apparently has no data, or a hypothesis that makes sense (Frugal to the point of vacuity).

At the Tumbld Thoughts microblog, Bradly Alicea looked at the nature of blogosphere academic activity, and its relationship to open-source publishing (Blogosphere review).

Finally, every month has its drinking vessel in which the waters become stormy. Recently in Aeon magazine, science writer David Dobbs published an article (Die, selfish gene, die) in which he noted that: "The selfish gene is one of the most successful science metaphors ever invented. Unfortunately, it’s wrong." This has generated a number of responses (as submitted by Ryan Gregory and Bjørn Østman), including those by PZ Myers from Pharyngula (Higher order thinking), Annalee Newitz from io9 (It's time to get skeptical about "the selfish gene"), and Larry Moran from Sandwalk (Razib Khan doesn't like Gould and doesn't like new-fangled ideas) (all of them arguing in favor of Dobbs, to one extent or another), and from Jerry Coyne from Why Evolution Is True (David Dobbs mucks up evolution, part I; and part II) and Razib Khan from Gene Expression (There is no revolution in genetics; and Evolutionary orthodoxy may be boring, but it is probably true) (who are against). David Dobbs has replied, as has Richard Dawkins.


Well, that's it for this month. While you wait for the next edition, you will find the Carnival of Evolution on Facebook and Twitter, as well as at the official Carnival of Evolution blog. Past posts and future hosts can be found on the Carnival index page.

The host of next month's Carnival will be Byte Size Biology.

You can submit posts for the next edition using the Carnival submission form (which requires you to log in), by commenting at the Carnival facebook page, or by sending an email to Bjørn Østman.

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