New findings challenge long-held assumptions about flightless bird evolution

University of Florida zoologists say that large flightless birds such as the ostrich and emu do not share a common flightless ancestor as once believed. Instead, each species individually lost flight after diverging from ancestors that did have the ability to fly.

Edward Braun and his fellow researchers began closely studying this group of flightless birds (known collectively as ratites) after they noticed that the ratites did not form a natural group based on their genetic makeup. Rather, they belonged to multiple related but distinct groups that contained another group of birds, the tinamous, with the ability to fly.

Previously, the ratites were used as a textbook example of vicariance, a term that describes the geographical division of a single species, resulting in two or more very similar sub-groups that can then undergo further evolutionary change and eventually become very distinct from one another.

Scientists assumed that a single flightless common ancestor of the ratites lived on the supercontinent of Gondwana, which slowly broke up into Africa, South America, Australia and New Zealand; once divided, the ancestor species evolved slightly in each new location to produce the differences among the present-day ratites, Braun explained. But in light of this new information, he said it’s more likely that the ratites’ ancestors distributed themselves among the southern continents after the breakup of Gondwana, which began about 167 million years ago, in a much more obvious way. They flew.

The study, appearing in the Proceedings of the National Academy of Sciences, has several important implications, says Braun. He contends it means some ratites, like the emus, are much more closely related to their airborne cousins, the tinamous, than they are to other ratites. And second, it means the ratites are products of parallel evolution – different species in significantly different environments following the exact same evolutionary course.

Although these new revelations teach evolutionary scientists a great deal, they also pose a great many new questions. For example, why did these birds evolve into such similar organisms in such different environments? “To know for sure, we’ll have to go into the lab and really study the genetics underlying the ratites’ developmental pathway,” Braun said. “But nobody would have asked that question without the type of data we’ve collected, which raises the question in the first place.”

Related:
Darwin’s Dilemma Solved?
Evolutionary Changes Not Always Small

Source: University of Florida

, ,

Comments are closed.

TAZOS POKEMON MEGA EVOLUTION COMPLETE SET 47/47 PERU 2019 RARE POGS FLIPS TAPS picture

TAZOS POKEMON MEGA EVOLUTION COMPLETE SET 47/47 PERU 2019 RARE POGS FLIPS TAPS

$210.00



2016 Pokemon XY Evolution #12 Charizard EX PSA 9 MINT picture

2016 Pokemon XY Evolution #12 Charizard EX PSA 9 MINT

$30.00



MITSUBISHI EVOLUTION RALLY CAR METAL WALL ART - ORIGINAL DIGITAL ART DESIGN picture

MITSUBISHI EVOLUTION RALLY CAR METAL WALL ART - ORIGINAL DIGITAL ART DESIGN

$17.60



EVOLUTION COIN HOPPER, 16.25-20.9 MM, W/ BULGIN CONNECTOR & PARALLEL RBM-255C-4F picture

EVOLUTION COIN HOPPER, 16.25-20.9 MM, W/ BULGIN CONNECTOR & PARALLEL RBM-255C-4F

$200.00



Panini Harry Potter Evolution Trading Cards Choose from All Cards 1-200 picture

Panini Harry Potter Evolution Trading Cards Choose from All Cards 1-200

$216.10



2023 Blizzard Legacy Collection BlizzCon Evolution Silver 5/49 Will Murai p9m picture

2023 Blizzard Legacy Collection BlizzCon Evolution Silver 5/49 Will Murai p9m

$224.50



Evolution Of Mankind Playing Cards picture

Evolution Of Mankind Playing Cards

$16.99



Pokemon Paldean Fates - Shiny Promo Sprigatito Evolution Set NM/M picture

Pokemon Paldean Fates - Shiny Promo Sprigatito Evolution Set NM/M

$12.00



EVolution Electric Vehicles 21

EVolution Electric Vehicles 21" LED Animated Christmas Musical Town Display

$150.00



Ace Martial Arts Supply Dragon Evolution Fantasy Sword picture

Ace Martial Arts Supply Dragon Evolution Fantasy Sword

$170.00



Powered by WordPress. Designed by WooThemes