Tiktaalik was a transitional fossil dating to around 375 million years ago that provides evidence of the evolution of fish to land-based tetrapods. Tiktaalik had wrist bones suggesting it could support itself on its front limbs, representing an intermediate form between fish and four-limbed animals. Studying fossils like Tiktaalik helps scientists understand how early ancestors transitioned from aquatic to terrestrial environments and evolved the ability to walk on land.

1. 1. Tiktaalik
https://www.palaeocast.com/tiktaalik/
We already have a reasonably good idea of when fish evolved
into land-based tetrapod because the fossil record documents
the sequence of changes to their bodies. One of the most iconic
specimens is Tiktaalik, a "transitional" fossil dating to around
375 million years ago. Tiktaalik is special, because though it
retains many fish-like characteristics, it also possesses wrist
bones, suggesting that it could support itself on its front limbs.
Fossils from rocks older than Tiktaalik lack these wrist bones
and are generally more fish-like. Fossils from younger rocks
include more tetrapod-like species, with distinct digits and
limbs.
Walking fish help people understand how we left the ocean. Our
ancestors' transition out of the water and onto the land was a
pivotal moment in evolution. No longer buoyed by water, early
tetrapods had to overcome gravity in order to move their bodies.
Exactly how those early pioneers first evolved the fundamental
capacity to walk has fascinated scientists for many years.
2. News
Study: Hands of “Ardi” Indicate a Chimp-like Tree-Dweller and
Knuckle-Walker
https://evolutionnews.org/2021/02/study-hands-of-ardi-indicate-
a-chimp-like-tree-dweller-and-knuckle-walker/
Recently we saw that a new study found the supposed human
ancestor Sahelanthropus Tchadensis had a chimp-like quadruped

2. body plan. It therefore should not be considered a human
ancestor. The hominin fossil Ardipithecus ramidus, or “Ardi,”
has been going through a similar evolution. Initially, Ardi was
widely called the “oldest human ancestor,” due to its supposed
skeletal traits that indicated an early bipedal (upright walking)
species. Lead researcher Tim White even called Ardi the
“Rosetta stone for understanding bipedalism.” But after Ardi
was officially announced, other papers strongly challenged the
claim that Ardi was bipedal. One article in Science commented
that “All of the Ar. ramidus bipedal characters cited also serve
the mechanical requisites of quadrupedality.” Another review in
Nature strongly argued that “the claim that Ardipithecus
ramidus was a facultative terrestrial biped is vitiated because it
is based on highly speculative inferences about the presence of
lumbar lordosis and on relatively few features of the pelvis and
foot.”
It must be the most common picture that used to explain the
concept ‘evolution’. The new discovery ‘Ardi’ attracts me that
people may find another good example to help us understand
how we evolved into bipedalism.
3. Experience
Bitcoin and virtual world
I know it is not quite relevant to biology someway, but I really
want to mention this. Bitcoin is a type of cryptocurrency. There
are no physical bitcoins, only balances kept on a public ledger
that everyone has transparent access to. All bitcoin transactions
are verified by a massive amount of computing power. Bitcoins
are not issued or backed by any banks or governments, nor are

3. individual bitcoins valuable as a commodity.
Every country issues its own currency that is regulated by the
corresponding government. We all know the function of
currency in global economy and how important it is. I think the
development of bitcoin is also an evolution of real gold coin to
virtual currency. From my perspective, when currency enters a
virtual world, all living things will enter the virtual world as
well.
4.