u/LogicalAttention9168

Traditionally, gnetophytes and conifers were placed on different divisions (Pinophyta vs Gnetophyta) within gymnosperms clade and gnetophytes were considered the sister group to all angiosperms because they have similar traits (vessel elements, flower-like structures). But recently, this has been largely disproven because DNA tests suggesting that this is because of convergent evolution. And modern scientists have shown that they are actually sister group to the pinaceae family. If they are sister group to the specific family pinaceae, they must be conifers or at least evolved from them. But the search results say the opposite of that saying that they are sister group to all conifers. If gnetophytes are the sister group to conifers and if they are not conifers, then all conifers must belong to the family pinaceae, which is not correct. And when we exclude gnetophytes from conifers, then conifers will be a paraphyletic group. But it is still considered a monophyletic group. Do you think that gnetophytes really evolve from conifers?

The last common ancestor of jawed vertebrates and jawless vertebrates (Lampreys) was a "soft bodied" primitive chordate (or an early "stem vertebrate") which only had a notochord but not a true backbone. If that ancestor wasn't a true vertebrate (because vertebrates must have a backbone and can't be soft bodied) but rather a primitive chordate with just a notochord and if they split off before backbone evolved, how its descendants (Jawless vertebrates and jawed vertebrates) can be classified as "vertebrates"?

Traditionally, textbooks taught us that bilaterally symmetrical animals can be categorized into 2 groups - protostomes and deuterostomes, based on whether their first dent in embryo becomes the mouth or the anus. But some recent studies showed that they were not valid evolutionary groups, saying that Urbilaterian (The last common ancestor of all bilaterally symmetrical animals) was likely a deuterostome-like animal and protostomes likely flipped their body plan later. However, different sources say different things now. Most still say that traditional grouping is the correct way, while few others say that recent scientific research is the correct. What do you think is the most correct?

Conifers first appeared over 300 million years ago, while ginkgos first appeared around 270 million years ago. The earliest conifers from 300 to 320 million years ago already looked very much like modern ones. They featured wind pollination, needle-like leaves, and cones as reproductive structures.
In contrast, ginkgos from 270 million years ago did not resemble modern ginkgos at all. Instead, they looked like primitive plants with leaves growing straight out of the main trunk.
This raises a question: why are ginkgos considered "living fossils" when conifers are older and often show even less physical change over time?

The last common ancestor of dolphins and sharks was an early jawed fish that roamed the oceans around 420 to 450 million years ago. Since this ancestor was already a fish, it possessed a streamlined body adapted to life in the water. Even when the ancestors of dolphins (tetrapods) left the water for a terrestrial existence, they still carried the genetic blueprint for that streamlined shape. Later, when the ancestors of cetaceans returned to the water, they likely reused those ancient genes to regain their streamlined form. Therefore, why is their fish-like body shape still considered a textbook example of convergent evolution?