Plants and Pollination

History: The very earliest photosynthesizing plants on Earth had only one cell, and they reproduced by mitosis: splitting themselves in half.

By about two billion years ago, some of these cells began to split themselves in a more sophisticated way, called meiosis, where there's a daddy cell and a mommy cell and each parent cell makes a new cell with a copy of half of its DNA. With all this mixing up of DNA, plants began to evolve much faster than they had before. Soon there were plants with more than one cell, likeseaweed

When the first plants like moss began to live on land ago, they developed a way to reproduce using spores instead.

Spores worked well for the moss, and also for the ferns that evolved later on. But these spores counted on falling on to wet ground; if they didn't find wet ground they just died.

When plants began to spread on far from the edges of streams, they needed a way to protect baby cells that fell on dry land. That's when the earliest plants gradually evolved hard covers for their baby cells, or seeds. Soon, there lots of seed plants, mainly pine trees, all over the land.

Beginning around the same time, a few plants were developing new ways to help out their reproduction: flowers, and fruit. Flowering plants needed bees to land on them and carry theirpollen from flower to flower. Bees and flowers evolved together, and they are symbiotic - bees can't live without flowers, and flowers can't live without bees. The earliest flowers developed as a way to attract insects and get them to help spread the plant's pollen far away from where the plant was growing.

Many plants, such as grass, weeds and even large pine trees, rely on the wind for pollination. The pollen is small and light, allowing it to be blown by the wind. The pollen lands on other plants and fertilizes them.

Why will a seed die if it grows directly under its parent?

Evolution of the Man

How does life come on the Earth in such variety. A scientist called Charles Darwin developed the Theory of Evolution, that states that Life evolved on Earth very slowly and by Natural Selection of species.

Scientists agree that human beings evolved from Apes some 5-7 million years ago (mya). Infact, Humans and Chimpanzees have the same ancestoral lineage, but followed different evolutionary paths. Our DNA is 98.4% similar to that of a chimpanzee!!

All human type of species are called Homo. There are many types of Homo creatures discovered, of which all but Homo Sapiens are now extinct. That means every human being on Earth today is a Homo Sapien. Let us follow the path of Evolution and see where we came from!

The human evolution started in Africa, and it is from there that humans spread around the world.

The earliest ancestor of Human is known to be Australopithecus – a creature half ape, half human. Full of hair, he did not know how to make any tools, but used sticks and bones as tools. Australopithecus is looks more Ape like than a human, and is not included in the Homo genre.

Around 2 mya, Homo Habilis (man with abilities) was evolved. Homo habilis could make some basic stone tools like axe-head and spears. He is also known as the Handy-Man. He lived in caves, and hunted animals. Using and making complex tools is an important sign of intelligence.

Around 1,5 million years ago, Homo Eretus evolved. Homo erectus means the man who can walk upright. The evidence was first found in Java, Indonesia, and so it is also often called as the Java Man.

Homo Neanderthalensis was the first human being in Europe. Its’ bones were found in the Neander Valley, Germany. Short, Stout and a lot like modern humans, the Neander Man probably knew the use of fire and used hide to cover themselves in the Cold.

Homo Neanderthalensis and all other species of humanoids were eventually replaced by Homo Sapiens, the man who can think. Homo Sapien evolved around 120,000 years ago. A woman skeleton found in Afria is often touted as the mother of the mankind, and is named Lucy.

The development of human brain , that consumes 20% of all enery produced in the body played a huge role in our evolution, away from the rest of the animals. The hairless body (to aid sweating) , the invention of simple tools, the control of Fire, domestication of animals and eventually Agriculture led to the modern human race.