Discovery of the Initial Limb on the Evolutionary Family Tree
In a groundbreaking discovery that sheds light on the history of animal evolution, scientists have finally traced the common ancestor of all animals on Earth. For decades, a debate raged among researchers about whether sea sponges or comb jellies were the group of animals that could be considered the sister to all other creatures.
New chromosomal analysis techniques have provided the answer to this long-standing question. The animal group identified as the sister to all other animals is, in fact, the sponges (Porifera). This surprising finding has scientists excited to investigate what this new knowledge can tell us about the mechanisms powering animal evolution.
Jackie Appel, a writer and editor from Pennsylvania with a background in astrophysics, has been sharing the weird wonders of this discovery with the world. Jackie writes for Popular Mechanics and is also active on the Popular Mechanics TikTok page, where she uses her voice to talk about science-y stories.
The key to this technique was looking at the placements of certain groups of genes in sponges and comb jellies compared to their closest single-cell non-animal relatives. In both the non-animals and the comb jellies, researchers found 14 groups of genes located on separate chromosomes. But in the sponges, researchers found that those 14 groups had been rearranged into 7 groups.
This rearrangement is significant because it suggests that the first split in the animal tree of life occurred around 600 million years ago. The first split resulted in the birth of two creatures: one being the ancestor of almost all animals, and the other being the ancestor of a specific group of modern-day animals. The comb jelly, it turns out, is the sister to all other animals, the first to branch off, and the most genetically isolated animal.
Jackie's writing focuses on sharing the incredible stories of the universe, and she has a deep love for storytelling, particularly about space and physics. Her full bio can be found on the Popular Mechanics website, where readers can learn more about her background and her passion for sharing science with anyone who wants to listen.
As we continue to unravel the mysteries of the animal kingdom, it's clear that there is still much to learn about our own evolutionary history. This latest discovery is just the beginning, and we can only imagine what other secrets are waiting to be uncovered.
