Which of the following statements are true?

I. The Nile perch introduced into Lake Victoria in east Africa led the extinction of more than 200 species of cichlid fish in the lake.

II. Stellar's sea cow and passenger pigeon became extinct due to overexploitation by humans.

III. Lantana and Eichhornia are invasive weeds in India.

IV. Species diversity increases as we move away from the equator towards the poles. 

Select the option containing the correct statements.

I, II, and III

The correct answer is Option (4) -I, II, and III

When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause the decline or extinction of indigenous species. The Nile perch introduced into Lake Victoria in east Africa led eventually to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake.

Humans have always depended on nature for food and shelter, but when ‘need’ turns to ‘greed’, it leads to over-exploitation of natural resources. Many species extinctions in the last 500 years (Steller’s sea cow, passenger pigeon) were due to overexploitation by humans.

When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause the decline or extinction of indigenous species. Example the environmental damage caused and threat posed to our native species by invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia).

The diversity of plants and animals is not uniform throughout the world but shows a rather uneven distribution. For many group of animals or plants, there are interesting patterns in diversity, the most well- known being the latitudinal gradient in diversity. In general, species diversity decreases as we move away from the equator towards the poles.