Algae constitute a polyphyletic group since they do not include a common ancestor, and although their plastids seem to have a single origin, from cyanobacteria, they were acquired in different ways.
ˈælɡiː kˈɑːnstɪtˌuːt ɐ pˌɑːlɪfaɪlˈɛɾɪk ɡɹˈuːp sˈɪns ðeɪ duːnˌɑːt ɪŋklˈuːd ɐ kˈɑːmən ˈænsɛstɚ, ænd ɔːlðˈoʊ ðɛɹ plˈæstɪdz sˈiːm tə hæv ɐ sˈɪŋɡəl ˈɔːɹɪdʒˌɪn, fɹʌm sˌaɪɐnˌɑːbɐktˈɪɹiə, ðeɪ wɜːɹ ɐkwˈaɪɚd ɪn dˈɪfɹənt wˈeɪz.