Really? Who observed this? It’s fantasy Re-create this scenario of your process. Mosquitos is what you’ll get
Uh, or preserved fossils and current living versions?
Today both eukaryotes and prokaryotes still exist. Eukaryotes can be found variously as single-celled organisms called protists, and as organized systems in multicellular organisms. The cells of all plants, animals and fungi are eukaryotes.
The origin of the eukaryotic cell is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. A number of approaches have been used to find the first eukaryote and their closest relatives. The
last eukaryotic common ancestor (LECA) is the hypothetical
last common ancestor of all living eukaryotes, and was most likely a
biological population.
[97]
Fossils[edit]
The timing of this series of events is hard to determine;
Knoll (2006) suggests they developed approximately 1.6–2.1 billion years ago. Some
acritarchs are known from at least 1.65 billion years ago, and the possible alga
Grypania has been found as far back as 2.1 billion years ago.
[100] The
Geosiphon-like fossil
fungus Diskagma has been found in paleosols 2.2 billion years old.
[101]
Organized living structures have been found in the
black shales of the Palaeoproterozoic Francevillian B Formation in Gabon, dated at 2.1 billion years old. Eukaryotic life could have evolved at that time.
[102] Fossils that are clearly related to modern groups start appearing an estimated 1.2 billion years ago, in the form of a
red algae, though recent work suggests the existence of fossilized
filamentous algae in the
Vindhya basin dating back perhaps to 1.6 to 1.7 billion years ago.
[103]
The presence of eukaryotic-specific
biomarkers (
steranes) in
Australian shales previously indicated that eukaryotes were present in these rocks dated at 2.7 billion years old,
[98][104] which was even 300 million years older than the first geological records of the appreciable amount of molecular oxygen during the
Great Oxidation Event. However, these Archaean biomarkers were eventually rebutted as later contaminants.
[105] Currently, putatively the oldest biomarker records are only ~800 million years old.
[106] In contrast, a molecular clock analysis suggests the emergence of sterol biosynthesis as early as 2.3 billion years ago,
[107] and thus there is a huge gap between molecular data and geological data, which hinders a reasonable inference of the eukaryotic evolution through biomarker records before 800 million years ago. The nature of steranes as eukaryotic biomarkers is further complicated by the production of sterols by some bacteria.
[108][109]
Whenever their origins, eukaryotes may not have become ecologically dominant until much later; a massive uptick in the zinc composition of marine sediments
800 million years ago has been attributed to the rise of substantial populations of eukaryotes, which preferentially consume and incorporate zinc relative to prokaryotes, approximately a billion years after their origin (at the latest).
[110]
In April 2019, biologists reported that the very large
medusavirus, or a relative, may have been responsible, at least in part, for the
evolutionary emergence of complex eukaryotic cells from simpler
prokaryotic cells.
[111]
