[생물.진화론] 물에서 육지로 나왔다가, 다시 물 속으로 들어감. 틱탈릭 물고기의 사촌격. 킥킥타니아. Qikiqtania wakei (새로운 엘피스토스테갈리아,elpistostegalian)

물고기가 물 속에서 살다가 육지로 나왔다는 가설에 대한 다른 증거자료이다. 틱탈릭의 사촌 격인 킥킥타니아 물고기는 물 속에서 살다가 육지(뭍)으로 나왔다가, '엇 안되겠는 걸' 하면서 다시 물 속으로 돌아갔다는 증거.

 

 

틱탈릭, 킥킥타니아 물고기가 얕은 물이나 개펄,진흙에서 생존 가능함. 이를 입증하는 방법은 이 물고기들의 뼈, 해부 구조에서 도출했는데, 이것들의 특징은 팔, 다리, 손가락, 발가락 등을 지니고 있음.

 

 

킥킥타니아 와케이 화석은  한 종에서 다른 종으로 일직선으로 진보한다는 진화론에 대한 반례 (반대사례)이다.

 

 

닐 슈빈(Neil Shubin)의 주장, 물 속의 물고기가 육지의 네발동물로 발전한 것이 아니라, 쌍방향으로 (물에서 육지로, 육지에서 물로) 진화했다. 

 

 

진화 모양새는 사다리 형태가 아니라, 나뭇가지 뻗침 모양새이다. (아래 그림 Branching Paths) 나무가지치기 길 모양새.

 

진화란 장미 덩쿨처럼, 여러가지 방향으로 뻗친 나무가지 모양새이고, 덤불 형태이다.

 

 

 

 

 

 

 

 

 

 

 

 

tetradpod,네발 동물, 사지 동물. (개구리 같은 양서류, 조류, 포유류) 한 쌍의 팔, 다리를 가진 척추동물.

: a vertebrate (such as an amphibian, a bird, or a mammal) with two pairs of limbs

 

Paleontologist 팰리-온톨로지스트. 고생물학자.

 

 

 

논문 제목. 캐나다 북극의 후기 데보니안 시기, 새로운 엘피스토스테갈리아 A new elpistostegalian from the Late Devonian of the Canadian Arctic 

 

저자. 토마스 스튜어트. 저스틴 렘버그. 아일리스 달리. 에드워드 대쉴러. 닐 슈빈. 

 

Thomas A. Stewart1,3,4, Justin B. Lemberg1,4, Ailis Daly1 , Edward B. Daeschler2  & Neil H. Shubin1 ✉

 

Nature 네이처 지. 2022년. June 17.

 

 

출처. 

 

 

 

 

 

Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes.

 

The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian Tiktaalik. Through a strict cladistic view, the order includes the terrestrial tetrapods.

 

What is special about lobe-finned fish?

Unlike other fish, Lobe-finned fish have a central appendage in their fins containing many bones and muscles. The fins are very flexible and potentially useful for supporting the body on land, as in lungfish and tetrapods (vertebrates with four limbs).

 

로브-핀드 물고기 (육기어류)의 지느러미 안에는 수많은 뼈와 근육을 포함한 주요 부속기관들이 있다. 지느러미는 폐어(lung-fish)와 네발어류처럼, 아주 유연하고 육지에서 활동할 수 있게끔 해준다.

 

 

 

 

 

 

 

Fig. 3 | Left pectoral fin of Q. wakei. Volume renderings of µCT scans of the

fin with scales removed. a,b, Dorsal (a) and ventral (b) views of the fin with

endoskeleton in grey and dermal rays in orange. Dotted lines indicate the

boundary between ulna and ulnare. The dashed line indicates position of

cross-section in e, which is oriented orthogonal to the plane of the fin web.

c, Endoskeleton viewed from the proximal side with humerus removed.

d, Reconstruction of endoskeletal elements with estimated boundary

between the radius and intermedium. Scale bar, 1 cm. e, Cross sections of

the fin rays, showing asymmetry in the size of dorsal and ventral hemitrichia.

f–k, Humerus in dorsal (f), pre-axial (anterior) (g), ventral (h), postaxial

(posterior) (i), proximal (j) and distal (k) perspectives. Scale bar, 1 cm. Proximal

is up in f–i. Dorsal is up in j and k. Abbreviations: ar, anterior radial; cap, caput

humeri; h, humerus; ir, intermedium; r, radius; rf, radial facet; m3, third

mesomere, u, ulna; ul, ulnare; uf, ulnar facet.

 

 

 

등 (dorsal) , 배 (ventral) 쪽 뼈 구조.   틱탈릭. 킥킥타니아 등 비교. 

 

 

 

 

SCIENCE

 

This fish evolved to walk on land — then said 'nope' and went back to the water

 

July 31, 20225:01 AM ET

 

KAI MCNAMEE (캐이 맥나미) 

 

 

 

킥킥타니아 와케이. (약간 노란 색 .중앙) 

An illustration of Qikiqtania wakei (center) in the water with its larger cousin, Tiktaalik roseae.

 

Alex Boersma

 

 

3억 7500만 년, 틱탈릭이라는 물고기는 바다에서 기어나왔고, 녹색 장어처럼 생겼다고 함. 

 

You may have come across a meme showing an ancient fish known as Tiktaalik.

 

It shows the green, eel-like creature crawling out of the sea about 375 million years ago — about the time that scientists say fish developed the physical characteristics to survive on land — only to be directed to turn around.

 

The joke, as far as the meme goes, is that the fish should crawl straight back into the water to avoid the woes of our modern times.

 

Now, a new study published in Nature suggests a relative of Tiktaalik – named Qikiqtania wakei – did just that.

 

 네이처 지에 발표. (닐 슈빈 Neil Shubin) 틱탈릭의 사촌 격인 킥킥타니아 와케이 물고기가 물에서 나와서 육지에서 살다가 다시 물 속으로 돌아갔다고 발표함.

 

"You had this evolutionary series of fish evolving to walk, but this one said, 'Eh, not going to do that one. I'm going back in,'" said Neil Shubin, a paleontologist at the University of Chicago who co-authored the study.

 

Shubin was part of the team who discovered Tiktaalik during a 2004 expedition in the Canadian Arctic. Qikiqtania was found on the same trip, but the fossil went mostly unstudied while the team focused on Tiktaalik.

 

 

 

"This new species is a very close cousin of Tiktaalik. We know that by looking at all the features," Shubin said. "In fact, it's a very close cousin of both Tiktaalik and creatures with arms and legs and fingers and toes, so-called tetrapods."

 

테트라포즈.(네발 동물, 두 팔, 두 다리 등)

 

 

 

Early tetrapods were likely spending more and more time out of the water during this period, Shubin said. The arrangement of bones and joints in these animals' fins was starting to resemble arms and legs, which would have allowed animals like Tiktaalik to prop themselves up in shallow water and survive on mudflats.

 

얕은 물이나 개펄,진흙에서 생존 가능함.

 

But Tom Stewart, an evolutionary biologist at Penn State who also worked on the study, said Qikiqtania's physiology suggested it was swimming in open water.

 

Qikiqtania's fins are the result of its swimming ancestors crawling onto land, then returning to the water.

 

"That's an unexpected pattern," he said. "That's not something that would have been predicted before we had a fossil like this."

 

 

A digital reconstruction of the pectoral fin of the Qikiqtania wakei fossil.

 

 

디지털 기술로 복원한, 킥킥타니아 와케이 물고기 화석, 가슴 지미러미. (pectoral fin) 

 

 

 

Tom Stewart

 

 

The study expands paleontologists' understanding of this period in evolutionary history by showing that animals weren't just evolving from water-based fish to land-based tetrapods.

 

"The transition from life in water to life on land was going both ways," Shubin said.

 

Qikiqtania is a vivid counterexample to the long-debunked, yet enduring myth that evolution is a linear progression from one species to the next.

 

"We get introduced to the idea of evolution through images like an ape that slowly stands upright and then produces a man walking," Stewart said. "Those are some of these classic, iconic teaching tools ... but really, evolution doesn't work in that way."

 

Shubin said evolution was more accurately described as a set of branching paths, rather than a ladder. "Evolution is much more of a bush," Shubin said, "a tree of creatures evolving in many different directions."

 

We'll see how the memes evolve from here.

 

 

출처

 

http:// https://n.pr/3d0zSnU

 

 

 

 

물고기 진화 , 계통발생 (Phylogeny)

 

 

 

Tetrapod 까지.