Evidence 3.1: TIMELINE

Events that culminated in the emergence of modern humans

Creation of THE solar system

Creation of the universe

Formation of planet earth

The solar system as we know it began life twisting through the universe without direction or form. About 4.6 billion years ago.

Big Bang theory is the most accepted theory of how the universe was created.

Earth formed 4.6 billion years ago.

Events that culminated in the emergence of modern humans

Appearence of the first forms of life

665 mya

Luca

360 mya

160 mya

URMETAZOAN

COELACANTH

JURAMAIA

3.8 bya

Origin of life

PRIMATES

URBILATERIAN

3.6 - 2.7 bya

Abiotic Synthesis 4.3 bya

570 - 550 mya

FIRST UNICELLULAR ORGANISMS

Three-domain system

TIMELINE of life

Early Hominins 7-6 mya

PARANTHROPUS 3-2 MYA

MODERN HUMANS (Homo sapiens) -TODAY

Australopithecines 5-3 mya

EARLY HOMO 3-1 MYA

• We can´t forget about Neanderthals, our closest extinct relatives. Some of the features of the skull include a large central facial area, angular cheekbones, and a large nose that humidifies and warms cold, dry air. Their bodies were shorter and heavier than ours and adapted to colder environments. But their brains were identical to ours, often in proportion to their muscular bodies.

• DNA was extracted from more than a dozen Neanderthal fossils, all from Europe. The Neanderthal Genome Project is one of the most exciting new directions in human origin research.

Referencias

• Universe, H. o. (n.d.). Formation and Evolution of the Universe. Retrieved from American Museum of Natural History: https://www.amnh.org/exhibitions/permanent/the-universe/the-universe/formation-and-evolution-of-the-universe#:~:text=Our%20universe%20began%20with%20an,stars%20and%20the%20first%20galaxies.
• Wong, J., & Hendry, L. (n.d.). The origin of our species. Natural History Museum. https://www.nhm.ac.uk/discover/the-origin-of-our-species.html
• Smithsonian National Museum of Natural History. (2022, July 7). Sahelanthropus tchadensis. The Smithsonian Institution’s Human Origins Program. https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis
• Su, D. F. (2013). The Earliest Hominins: Sahelanthropus, Orrorin, and Ardipithecus. Nature news. https://www.nature.com/scitable/knowledge/library/the-earliest-hominins-sahelanthropus-orrorin-and-ardipithecus-67648286/
• McHenry, H., & Johanson, D. C. (2023, November 3). Australopithecus. Encyclopædia Britannica. https://www.britannica.com/topic/Australopithecus
• Clarke, R. J. (2014). Australopithecines. SpringerLink. https://link.springer.com/referenceworkentry/10.1007/978-1-4419-0465-2_684
• Las Vegas NHM. (2022, July 27). Australopithecines existed one million years earlier than expected. Las Vegas NHM. https://www.lvnhm.org/post/australopithecines-exist-earlier-than-expected
• TOI Education, (2023, May 23), The times of India, https://timesofindia.indiatimes.com/education/learning-with-toi/how-the-earth-formed-and-life-evolved-explained/articleshow/100436478.cms
• Pavid, K. (n.d.). https://www.nhm.ac.uk/discover/how-our-solar-system-was-born.html

Referencias

• Arambourg, C., Coppens, Y., 1968. Sur la decouverte dans le Pleistocene inferieur de la valle de l'Omo (Ethiopie) d'une mandibule d'Australopithecien. Comptes Rendus des seances de l'Academie des Sciences 265, 589-590.
• Susan C. Antón et al. , Evolution of early Homo: An integrated biological perspective.Science345,1236828(2014).DOI:10.1126/science.1236828
• Sánchez, S. A. (2020, November 24). La Teoría de la síntesis abiótica: Qué Es y Qué preguntas intenta responder. Psicología y Mente. https://psicologiaymente.com/cultura/teoria-sintesis-abiotica
• ABC.es. (2021, July 7). Luca, El primer ser vivo de la tierra, era Una bacteria. Diario ABC. https://www.abc.es/ciencia/abci-luca-primer-vivo-tierra-bacteria-202107071237_noticia.html?ref=https%3A%2F%2Fwww.abc.es%2Fciencia%2Fabci-luca-primer-vivo-tierra-bacteria-202107071237_noticia.html
• Weiss, M., Sousa, F., Mrnjavac, N., Neukirchen, S., Roettger, M., Nelson-Sathi, S., & Martin, W. (2016, July 25). The physiology and habitat of the last universal common ancestor. Nature News. https://www.nature.com/articles/nmicrobiol2016116
• Woolfson, A. Origins of life: An improbable journey. Nature 520, 617–618 (2015). https://doi.org/10.1038/520617a
• Pilcher, H. Back to our roots. Nature 435, 1022–1023 (2005). https://doi.org/10.1038/4351022a
• Arthur, W., & Arthur, S. (2014). The enigmatic urbilaterian. In Evolving Animals: The Story of our Kingdom (pp. 77-84). Cambridge: Cambridge University Press. doi:10.1017/CBO9781107279117.009
• A Fish Caught in Time by Samantha Weinberg, Harper Collins, 2000
• Fossil Fish Found Alive. Discovering the Coelacanth by Sally M. Walker, Carolrhoda Books, Inc., 2002
• History of the Coelacanth Fishes by Peter L. Forey, Chapman & Hall, 1998.

Coelacanths might best be described as occupying a side branch in the basal portion of the vertebrate lineage, closely related to but distinct from the ancestor of tetrapods (four-legged vertebrates).

The last common ancestor of the bilaterian clade. At some point in the distant past, bilateral symmetry must have originated, and the first animal displaying it was the urbilaterian.

LUCA

Early Homo

The new environmental data show that Homo evolved under unpredictable long-term habitat conditions that replaced the underlying trend for aridity. The new fossils support the existence of several early Homo groups with overlapping body, brain, and tooth sizes, with H. habilis and H. rudolfensis represent the minor and major variants, respectively.Although more fossils and archaeological discoveries will advance our understanding of early human evolution, the comparative biology of mammals (including humans) will continue to provide a valuable framework for interpreting the data.

The creature is the earliest known example of an animal whose kind evolved to provide nourishment to their unborn through a placenta. Its features set it apart from marsupial mammals, which adopt a very different reproductive strategy.

Abiotic synthesis theory

This theory is the one that explains better the origin of life. It says that thanks to the environment of ancient Earth, various reactions happened and the result was the creation of the precursors of biomolecules. The earth's elements were carbon dioxide, nitrogen, hydrogen, water, methane, and ammonia.

Australopithecines

5-3 million years ago

This one includes the famous Australopithecus, popularized by the discovery of "Lucy". Her bones helped scientists to confirm that they walked on two legs. Thanks to more fossils found, experts found that they had many manlike characteristics but also apelike. They were bipedal and had small teeths, but they also had larger cheeks than us and a small brain (but not as small as the early hominis). Lucy was an Australopithecus afarensis, but there were also Australopithecus anamensis, Australopithecus sediba and Australopithecus africanus.

This gave rise to bacteria and archaea, which have no nucleus or other sub-cellular organelles.

We also have stromatolites, about 3.5 byo, as evidence of early life, specifically prokaryotes.

It grew larger thanks to countless collisions between dust particles, asteroids, and other growing planets, including one last giant impact that threw enough rock, gas, and dust into space to form the moon.

Formation of planet Earth

The Earth formed about 4.6 billion years ago. It started with a cloud of gas and dust in space called a nebula. As more and more particles collided, they formed larger objects called planetesimals, eventually, they grew in size and became protoplanets.

Gravitational collapse

This giant cloud was made up of dust, hydrogen, and other gases. It began to collapse in on itself after becoming unstable. Dust and gas were tugged in the center of the cloud, making its core dense and hot. Making the sun.

Heavy elements began sinking past the oceans and magma toward the planet's center. As this occurred, Earth became differentiated into layers, with the outermost layer being a solid covering of relatively lighter material while the denser, molten material sunk to the center.

The asteroid belt

Rocks that escaped the pull of planets were left as asteroids, scattered through the solar system without a permanent home. Many of these rocks orbit the Sun in an area between Mars and Jupiter known as the asteroid belt.Many of the asteroids in the solar system melted early on in their history to form an iron core and rocky mantle. The bodies that didn’t melt are a type of meteorite known as chondrites - sedimentary rocks that formed in the early solar nebula.

Early Hominis

7-6 millions years ago

It has been found that we probably evolved from chimpanzees. One of the first characteristics of our evolution was the reduction of the size of our canines and bipedalism. About the environment where they lived, the skull of a Sahelanthropus tchandesis was found in Chad, West-Central Africa. Thanks to their bipedalism it is thought that they went back and forth from forest at the edge of lakes to savanna woodland to open grassland. Other examples of the Early Hominis are Orrorin tugenensis, Ardipithecus kadabba, and Ardipithecus ramidus.

Formation of planets

As the cloud around the Sun began to cool, it formed different types of solid material. Gradually they got larger and larger, sweeping up all the leftover dust, until they grew into the planets we recognize today.

• The hot, rocky material near the centre of the solar system was sculpted into terrestrial planets with metal cores: Mercury, Venus, Earth and Mars.
• And on the cool edges, the gas and ice giants were born: Saturn, Jupiter, Neptune, and Uranus.

MODERN HUMANS

HOMO SAPIENS

The species to which you and every other being on this planet belong is Homo sapiens. Homo sapiens appeared in Africa 300,000 years ago during rapid climate change. Like other early humans who lived during this time, they gathered food, hunted, and developed behaviors that helped them survive in their unstable environment. Anatomically, modern humans are generally characterized by a lighter skeletal structure compared to early humans. The modern human brain is very large and varies in size by population group, male and female, but the average size is about 1,300 cm3. To accommodate this large brain, it was necessary to reshape the skull into something considered "modern". Scientists sometimes use the term "anatomically modern Homo sapiens" to refer to prehistoric members of our species.

The Big Bang

Approximately 14 billion years ago, the universe was very different as it is now. "Our universe began with an explosion of space itself - the Big Bang. Starting from extremely high density and temperature, space expanded, the universe cooled, and the simplest elements formed. Gravity gradually drew matter together to form the first stars and the first galaxies.." (Museum of History, n.d.)

LUCA

Last Ultimate Common Ancestor or LUCA for its initials. Is the oldest living being that we have ever found. As the name suggests, is the common ancestor for all forms of life today. LUCA was a bacteria part of the philo planctomycetes.

Tiktaalik (375 mya). is a fossil of a creature with traits found in both fish and tetrapods. This was the link between fish and land animals.

Pederpes (359 - 345 mya). very important entry into the fossil record as it represents the first tetrapod to evolve to a primarily terrestrial‭ (‬land-based‭) ‬lifestyle.‭

PARANTHROPUS

3 - 2 MILLION YEARS AGO

This name was generally rejected for the new species. Many paleoanthropologists felt it was premature to name a new species based on a single incomplete mandible. Paranthropus taxa, which includes Paranthropus aethiopicus, Paranthropus boisei, and Paranthropus robustus discovered in East and Southern Africa. Some researchers have suggested that Homo and Paranthropus may be related taxa. That is, they shared a most recent common ancestor that was not shared with any other hominin taxon.