Sexual reproduction, genetic material from two parents, emerged as a fundamental evolutionary innovation, before the advent of multicellular life forms. This critical development enabled the mixing of genetic material, leading to increased genetic diversity and adaptability among early eukaryotic organisms, setting the stage for the complex tapestry of life that would eventually populate Earth.
Sexual Reproduction Read More »
An example of early live birth is the protomammal Kayentatherium, Jurassic period. This cynodont is related to early mammals and its clutch size suggested egg-laying, providing clues about the transition to live birth. The switch to live birth in mammals, including marsupials and placentals, likely evolved once at their common ancestor, suggesting live birth in mammals
Mammals: First Live Births Read More »
After about 320 million years, the next significant leap in egg evolution came with reptiles, which developed amniotic eggs. These eggs have a protective shell and specialized membranes to support development outside of water, enabling reptiles to lay eggs in terrestrial environments.
Reptile Amniotic Eggs Read More »
The evolution of egg-laying evolved before fish. It is thought to have developed with or shortly after the emergence of the first multicellular animals, around 640 million years ago.
Both reptiles and our ancestor synapsids evolved from amphibians. While reptiles evolved better amniotic eggs, synapsid eggs were like amphibian eggs. Synapsid’s birthing process eventually led to mammalian live births. These are the animals that evolved Complex Sentience, the ability to feel various emotions. While it is unknown when this complex spectrum fully evolved, it
Early Complex Sentience Emerges: Dimetrodon Read More »
Class: Mammaliaforms or maybe Synapsida Time Period: Late Triassic to Early Jurassic Diet: Likely Herbivore Morganucodon is an example of a plant eater likely similar to our direct-line ancestors around this time. It is not a direct human ancestor but is among the early mammaliaforms, close to the lineage leading to true mammals. It likely
Morganucodon: An Early Mammalian Herbivore Read More »
Plesiadapis, a proto-primate, is an example of a fruit-insect eater likely similar to our direct-line ancestors around this time. Class: Mammal; Early Primate (Plesiadapiformes) Time Period: Late Paleocene Diet: Likely Frugivorous/Insectivorous
Plesiadapis: First fruit-insect eaters. Read More »
Creatures of this time evolved into fish (us), jellyfish, cephlapods, and arthropods. In the deep waters of the late Precambrian era, the seeds of sentience were sown with the evolution of the earliest common ancestors to later cephalopods and fish. These primordial creatures, equipped with the most basic nervous systems, embarked on the path toward
Presentient Animals Emerge: The Ediacaran Prelude Read More »
The emergence of the first brains were likely in the earliest known hunters. By about 520 million years ago, hunters roamed the seas. In the Cambrian explosion, a period of rapid evolutionary development that began around 541 million years ago, the earliest known animals with structures recognizable as brains made their debut in the Earth’s
Earliest Known Hunter Read More »
The appendix is a small, finger-shaped pouch attached to the large intestine. It has long been considered a vestigial organ, meaning that it has no function in the human body. However, recent research suggests that the appendix may actually serve as a reservoir for beneficial gut bacteria. The appendix is an example of a Phenotype
The millipede Pneumodesmus newmani is the oldest air-breathing animal known to date. This ancient denizen of the Scottish waters once roamed the Earth during the early Silurian era. The millipede likely supplemented its oxygen intake through air as well as using its gills while in water.  Â
Oldest Known Air Breather Read More »
Around 1.7 billion years ago, a branch of protozoa, an advanced branch of the eukaryote cells, split into animals, plants, and fungi. These three separate lineages are the ancestors of modern plants, fungi and animals. 1.7 billion years ago: Plants diverge from the common protozoa ancestor. 1.5 billion years ago: Fungi and animal branch emerges.
Animals, Plants, and Fungi Split Read More »
The earliest known vertebrates originated about 530 million years ago during the Cambrian explosion.Â
First Vertebrates Read More »
Through genetic analyses, scientists now believe the Comb Jellyfish is the earliest known true animal to evolve on Earth. Prior to this genetic analyses, simple sponges were thought to have evolved first.
First True Animals – Comb Jellyfish Read More »
Organisms that consist of more than one cell took several billion years to evolve from unicellular organisms. All species of animals, land plants and most fungi are multicellular, as well as many algae. A few organisms are partially both such as slime molds and social amoebae.
First Multicellular Animals Read More »
Within mammals, only primates have binocular vision, grasping hands, and flat nails–instead of claws. Purgatorius might have had all three earning it the earliest known proto-primate label. It lived in Eastern Montana about 66 million years ago during the very last years of the Cretaceous period. It lived through the K-T extinction event and the extinction
Purgatorius — Earliest known proto-primate. Read More »
Explore insights into science, philosophy, and history. This community features the writings of Mike Prestwood, a natural philosopher. This throwback title signifies his dedication to weaving together science, philosophy, and history. Engage in insightful discussions in a moderated, safe space where the realms of the irrational and unknowable are respectfully acknowledged but left at the doorway. Ready to connect with like-minded thinkers?
