Diversity and Abundance of life - Field Natural History - Lecture Notes, Study notes of History

Download Diversity and Abundance of life - Field Natural History - Lecture Notes and more Study notes History in PDF only on Docsity! LECTURE 1 B. Diversity and abundance of life. 1. As scientists have taken a closer look, they have found many more organisms that were less conspicuous, like fungi and insects. a. Reports of the number of species of organisms identified to date range from 1.4 million (your book) to 2.1 million. The latter figure is probably closer. b. Over a million of insects species have already been identified, with about 8,000 new species described every year. c. A conservative estimate is that there are 5 million species of insects in the world. Some estimates put the total number of tropical insects alone at 30 million! d. This should be no surprise; insects comprise 70% of all currently known species. e. Compared to insect numbers, there are only about 9,700 species of birds and 4,600 species of mammals. 2. It is very clear that early scientists overlooked many, many organisms. a. A new whale species b. A species represents the lowest level of classification. i. In Latin, species means ‘kind’, as in ‘a kind of bird’ or ‘a kind of primate. ii. [Latin sapi ns, sapient-, present participle of sapere, to taste, be wise] iii. sapiens belong to a larger group (a Genus) known as Homo. [from Gk. homos "one and the same,"] 3. Believe it or not, we still find new species. a. A new primate species Chiropotes israelita. b. By reevaluating it’s geographic distribution, it’s visible features (morphology) and using molecular techniques – examining the chromosome arrangements and the DNA sequence, Brazilian scientists have confirmed that C. satanas chiropotes is in fact C. israelita. 4. A new genus of plant – Hooglandia 5. A new insect order – the first since 1914! [Mantophasmatodea] 6. The central issue is, we don’t how important any of these organisms are. Docsity.com