tonight though be discussing jeremy dasilva's new book first steps held upright walking made of human. and it dasilva explains the history of bipedalism the ability unique to humans among living mammals to walk on two legs he makes the case bipedalism is a crucial change 11 the evolution of humans despite the difficulties to the promo ever after. publisher weekly praises desilva's love for fossil discovery and colleagues in the wonders he experience examining's bones firsthand. his ability to turn anatomical evidence into a focused tale of human evolution and his enthusiasm for research will leave readers both informed and uplifted. i'm so pleased to turn things over to our speaker the digital podium is yours, jeremy and kate. >> thank you. now i really depression at the introduction. hi kate thanks her being here in doing this. that great to see you thanks so much. and to the bookstore i'm delighted to have the opportunity to pepper jury with questions about his fabulous new book which is about all the things that i get most excited to write about. it is really a pleasure to be here.